Note: Descriptions are shown in the official language in which they were submitted.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
1
SLURRY DISTRIBUTOR WITH A PROFILING MECHANISM, SYSTEM, AND METHOD
FOR USING SAME
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the benefit of non-provisional
patent
application 13/659,516, filed October 24, 2012, entitled "Slurry Distributor,
System, and
Method for Using Same" and continuation-in-part patent application 13/844,550
filed
March 15, 2013 entitled "Slurry Distributor with a Profiling Mechanism,
System, and
Method for Using Same."
[0002] All of the foregoing related applications are incorporated in their
entireties
herein by this reference.
BACKGROUND
[0003] The present disclosure relates to continuous board (e.g., wallboard)
manufacturing processes and, more particularly, to an apparatus, system and
method
for the distribution of an aqueous calcined gypsum slurry.
[0004] It is well-known to produce gypsum board by uniformly dispersing
calcined
gypsum (commonly referred to as "stucco") in water to form an aqueous calcined
gypsum slurry. The aqueous calcined gypsum slurry is typically produced in a
continuous manner by inserting stucco and water and other additives into a
mixer which
contains means for agitating the contents to form a uniform gypsum slurry. The
slurry is
continuously directed toward and through a discharge outlet of the mixer and
into a
discharge conduit connected to the discharge outlet of the mixer. An aqueous
foam can
be combined with the aqueous calcined gypsum slurry in the mixer and/or in the
discharge conduit. The stream of slurry passes through the discharge conduit
from
which it is continuously deposited onto a moving web of cover sheet material
supported
by a forming table. The slurry is allowed to spread over the advancing web. A
second
web of cover sheet material is applied to cover the slurry and form a sandwich
structure
of a continuous wallboard preform, which is subjected to forming, such as at a
conventional forming station, to obtain a desired thickness. The calcined
gypsum reacts
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
2
with the water in the wallboard preform and sets as the wallboard preform
moves down
a manufacturing line. The wallboard preform is cut into segments at a point
along the
line where the wallboard preform has set sufficiently, the segments are
flipped over,
dried (e.g., in a kiln) to drive off excess water, and processed to provide
the final
wallboard product of desired dimensions.
[0005] Prior devices and methods for addressing some of the operational
problems
associated with the production of gypsum wallboard are disclosed in commonly-
assigned U.S. Patent Nos. 5,683,635; 5,643,510; 6,494,609; 6,874,930;
7,007,914; and
7,296,919, which are incorporated herein by reference.
[0006] The weight proportion of water relative to stucco that is combined
to form a
given amount of finished product is often referred to in the art as the "water-
stucco ratio"
(WSR). A reduction in the WSR without a formulation change will
correspondingly
increase the slurry viscosity, thereby reducing the ability of the slurry to
spread on the
forming table. Reducing water usage (i.e., lowering the WSR) in the gypsum
board
manufacturing process can yield many advantages, including the opportunity to
reduce
the energy demand in the process. However, spreading increasingly viscous
gypsum
slurries uniformly on the forming table remains a great challenge.
[0007] Furthermore, in some situations where the slurry is a multi-phase
slurry
including air, air-liquid slurry separation can develop in the slurry
discharge conduit from
the mixer. As WSR decreases, the air volume increases to maintain the same dry
density. The degree of air phase separated from the liquid slurry phase
increases,
thereby resulting in the propensity for larger mass or density variation.
[0008] It will be appreciated that this background description has been
created by
the inventors to aid the reader and is not to be taken as an indication that
any of the
indicated problems were themselves appreciated in the art. While the described
principles can, in some aspects and embodiments, alleviate the problems
inherent in
other systems, it will be appreciated that the scope of the protected
innovation is
defined by the attached claims and not by the ability of any disclosed feature
to solve
any specific problem noted herein.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
3
SUMMARY
[0009] In one aspect, the present disclosure is directed to embodiments of
a slurry
distribution system for use in preparing a gypsum product. In one embodiment,
a slurry
distributor can include a feed conduit and a distribution conduit in fluid
communication
therewith. The feed conduit can include a first feed inlet in fluid
communication with the
distribution conduit and a second feed inlet disposed in spaced relationship
with the first
feed inlet and in fluid communication with the distribution conduit. The
distribution
conduit can extend generally along a longitudinal axis and include an entry
portion and
a distribution outlet in fluid communication therewith. The entry portion is
in fluid
communication with the first and second feed inlets of the feed conduit. The
distribution
outlet extends a predetermined distance along a transverse axis, which is
substantially
perpendicular to the longitudinal axis.
[0010] In other embodiments, a slurry distributor includes a feed conduit
and a
distribution conduit. The feed conduit includes a first entry segment with a
first feed
inlet and a second entry segment with a second feed inlet disposed in spaced
relationship to the first feed inlet. The distribution conduit extends
generally along a
longitudinal axis and includes an entry portion and a distribution outlet in
fluid
communication with the entry portion. The entry portion is in fluid
communication with
the first and second feed inlets of the feed conduit. The distribution outlet
extends a
predetermined distance along a transverse axis. The transverse axis is
substantially
perpendicular to the longitudinal axis. The first and second feed inlets each
has an
opening with a cross-sectional area. The entry portion of the distribution
conduit has an
opening with a cross-sectional area which is greater than the sum of the cross-
sectional
areas of the openings of the first and second feed inlets.
[0011] In other embodiments, a slurry distributor includes a feed conduit,
a
distribution conduit, and at least one support segment. The feed conduit
includes a first
entry segment with a first feed inlet and a second entry segment with a second
feed
inlet disposed in spaced relationship to the first feed inlet. The
distribution conduit
extends generally along a longitudinal axis and includes an entry portion and
a
distribution outlet in fluid communication with the entry portion. The entry
portion is in
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
4
fluid communication with the first and second feed inlets of the feed conduit.
Each
support segment is movable over a range of travel such that the support
segment is in a
range of positions over which the support segment is in increasing compressive
engagement with a portion of at least one of the feed conduit and the
distribution
conduit.
[0012] In another aspect of the present disclosure, a slurry distributor
can be placed
in fluid communication with a gypsum slurry mixer adapted to agitate water and
calcined
gypsum to form an aqueous calcined gypsum slurry. In one embodiment, the
disclosure
describes a gypsum slurry mixing and dispensing assembly which includes a
gypsum
slurry mixer adapted to agitate water and calcined gypsum to form an aqueous
calcined
gypsum slurry. A slurry distributor is in fluid communication with the gypsum
slurry
mixer and is adapted to receive a first flow and a second flow of aqueous
calcined
gypsum slurry from the gypsum slurry mixer and distribute the first and second
flows of
aqueous calcined gypsum slurry onto an advancing web.
[0013] The slurry distributor includes a first feed inlet adapted to
receive the first flow
of aqueous calcined gypsum slurry from the gypsum slurry mixer, a second feed
inlet
adapted to receive the second flow of aqueous calcined gypsum slurry from the
gypsum
slurry mixer, and a distribution outlet in fluid communication with both the
first and the
second feed inlets and adapted such that the first and second flows of aqueous
calcined
gypsum slurry discharge from the slurry distributor through the distribution
outlet.
[0014] In another embodiment, a slurry distributor includes a feed conduit
and a
distribution conduit. The feed conduit includes an entry segment with a feed
inlet and a
feed entry outlet in fluid communication with the feed inlet. The entry
segment extends
along a first feed flow axis. The feed conduit includes a shaped duct having a
bulb
portion in fluid communication with the feed entry outlet of the entry
segment. The feed
conduit includes a transition segment in fluid communication with the bulb
portion. The
transition segment extends along a second feed flow axis, which is in non-
parallel
relationship with the first feed flow axis.
[0015] The distribution conduit extends generally along a longitudinal axis
and
includes an entry portion and a distribution outlet in fluid communication
with the entry
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
portion. The entry portion is in fluid communication with the feed inlet of
the feed
conduit. The distribution outlet extends a predetermined distance along a
transverse
axis, which is substantially perpendicular to the longitudinal axis.
[0016] The bulb portion has an area of expansion with a cross-sectional
flow area
that is greater than a cross-sectional flow area of an adjacent area upstream
from the
area of expansion relative to a flow direction from the feed inlet toward the
distribution
outlet distribution conduit. The shaped duct has a convex interior surface in
confronting
relationship with the feed entry outlet of the entry segment.
[0017] In still another embodiment, a slurry distributor includes a
bifurcated feed
conduit and a distribution conduit. The bifurcated feed conduit includes a
first and a
second feed portion each having an entry segment with a feed inlet and a feed
entry
outlet in fluid communication with the feed inlet, a shaped duct having a bulb
portion in
fluid communication with the feed entry outlet of the entry segment, and a
transition
segment in fluid communication with the bulb portion. The entry segment
extends
generally along a vertical axis. The transition segment extends along a
longitudinal
axis, which perpendicular to the vertical axis.
[0018] The distribution conduit extends generally along the longitudinal
axis and
includes an entry portion and a distribution outlet in fluid communication
with the entry
portion. The entry portion is in fluid communication with the first and second
feed inlets
of the feed conduit. The distribution outlet extends a predetermined distance
along a
transverse axis, which is substantially perpendicular to the longitudinal
axis.
[0019] The first and second bulb portions each has an area of expansion
with a
cross-sectional flow area that is greater than a cross-sectional flow area of
an adjacent
area upstream from the area of expansion relative to a flow direction from the
respective
first and second feed inlets toward the distribution outlet distribution
conduit. The first
and second shaped ducts each has a convex interior surface in confronting
relationship
with the respective first and second feed entry outlets of the first and
second entry
segments.
[0020] In another embodiment, a slurry distributor includes a distribution
conduit and
a slurry wiping mechanism. The distribution conduit extends generally along a
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
6
longitudinal axis, a distribution outlet in fluid communication with the entry
portion, and a
bottom surface extending between the entry portion and the distribution
outlet. The
distribution outlet extends a predetermined distance along a transverse axis,
which is
substantially perpendicular to the longitudinal axis. The slurry wiping
mechanism
includes a movable wiper blade in contacting relationship with the bottom
surface of the
distribution conduit. The wiper blade is reciprocally movable over a clearing
path
between a first position and a second position. The clearing path is disposed
adjacent
the distribution outlet.
[0021] In still another embodiment, a slurry distributor includes a
distribution conduit
and a profiling mechanism. The distribution conduit extends generally along a
longitudinal axis and includes an entry portion and a distribution outlet in
fluid
communication with the entry portion. The distribution outlet extends a
predetermined
distance along a transverse axis, which is substantially perpendicular to the
longitudinal
axis. The distribution outlet includes an outlet opening having a width, along
the
transverse axis, and a height, along a vertical axis mutually perpendicular to
the
longitudinal axis and the transverse axis.
[00221 The profiling mechanism includes a profiling member in contacting
relationship with the distribution conduit. The profiling member is movable
over a range
of travel such that the profiling member is in a range of positions over which
the profiling
member is in increasing compressive engagement with a portion of the
distribution
conduit adjacent the distribution outlet to vary the shape and/or size of the
outlet
opening.
[00231 In another aspect of the present disclosure, the slurry distributor
can be used
in a cementitious slurry mixing and dispensing assembly. For example, a slurry
distributor can be used to distribute an aqueous calcined gypsum slurry upon
an
advancing web. In other embodiments, a gypsum slurry mixing and dispensing
assembly includes a mixer and a slurry distributor in fluid communication with
the mixer.
The mixer is adapted to agitate water and calcined gypsum to form an aqueous
calcined
gypsum slurry. The slurry distributor includes a feed conduit and a
distribution conduit:
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
7
[0024] The feed conduit includes a first entry segment with a first feed
inlet and a
second entry segment with a second feed inlet disposed in spaced relationship
to the
first feed inlet. The first feed inlet is adapted to receive a first flow of
aqueous calcined
gypsum slurry from the gypsum slurry mixer. The second feed inlet is adapted
to
receive a second flow of aqueous calcined gypsum slurry from the gypsum slurry
mixer.
[0025] The distribution conduit extends generally along a longitudinal axis
and
includes an entry portion and a distribution outlet in fluid communication
with the entry
portion. The entry portion is in fluid communication with the first and second
feed inlets
of the feed conduit. The distribution outlet extends a predetermined distance
along a
transverse axis. The transverse axis is substantially perpendicular to the
longitudinal
axis. The distribution outlet is in fluid communication with both the first
and the second
feed inlets and is adapted such that the first and second flows of aqueous
calcined
gypsum slurry discharge from the slurry distributor through the distribution
outlet.
[0026] The first and second feed inlets each has an opening with a cross-
sectional
area. The entry portion of the distribution conduit has an opening with a
cross-sectional
area which is greater than the sum of the cross-sectional areas of the
openings of the
first and second feed inlets.
[0027] A cementitious slurry mixing and dispensing assembly including a
mixer
adapted to agitate water and a cementitious material to form an aqueous
cementitious
slurry and a slurry distributor in fluid communication with the mixer. The
slurry
distributor can be any one of the various embodiments of a slurry distributor
following
principles of the present disclosure.
[0028] In still another aspect of the present disclosure, the slurry
distribution system
can be used in a method of preparing a cementitious product. For example, a
slurry
distributor can be used to distribute an aqueous calcined gypsum slurry upon
an
advancing web.
[0029] In some embodiments, a method of distributing an aqueous calcined
gypsum
slurry upon a moving web can be performed using a slurry distributor
constructed
according to principles of the present disclosure. A first flow of aqueous
calcined
gypsum slurry and a second flow of aqueous calcined gypsum slurry are
respectively
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
8
passed through a first feed inlet and a second feed inlet of the slurry
distributor. The
first and second flows of aqueous calcined gypsum slurry are combined in the
slurry
distributor. The first and second flows of aqueous calcined gypsum slurry are
discharged from a distribution outlet of the slurry distributor upon the
moving web.
[0030] In other embodiments, a method of preparing a gypsum product can be
performed using a slurry distributor constructed according to principles of
the present
disclosure. A first flow of aqueous calcined gypsum slurry is passed at an
average first
feed velocity through a first feed inlet of a slurry distributor. A second
flow of aqueous
calcined gypsum slurry is passed at an average second feed velocity through a
second
feed inlet of the slurry distributor. The second feed inlet is in spaced
relationship to the
first feed inlet. The first and second flows of aqueous calcined gypsum slurry
are
combined in the slurry distributor. The combined first and second flows of
aqueous
calcined gypsum slurry are discharged at an average discharge velocity from a
distribution outlet of the slurry distributor upon a web of cover sheet
material moving
along a machine direction. The average discharge velocity is less than the
average first
feed velocity and the average second feed velocity.
[0031] In another embodiment, a method of preparing a cementitious product
can be
performed using a slurry distributor constructed according to principles of
the present
disclosure. A flow of aqueous cementitious slurry is discharged from a mixer.
A flow of
aqueous cementitious slurry is passed at an average feed velocity through a
feed inlet
of a slurry distributor along a first feed flow axis. The flow of aqueous
cementitious
slurry is passed into a bulb portion of the slurry distributor. The bulb
portion has an area
of expansion with a cross-sectional flow area that is greater than a cross-
sectional flow
area of an adjacent area upstream from the area of expansion relative to a
flow
direction from the feed inlet. The bulb portion is configured to reduce the
average
velocity of the flow of aqueous cementitious slurry moving from the feed inlet
through
the bulb portion. The shaped duct has a convex interior surface in confronting
relationship with first feed flow axis such that the flow of aqueous
cementitious slurry
moves in radial flow in a plane substantially perpendicular to the first feed
flow axis The
flow of aqueous cementitious slurry is passed into a transition segment
extending along
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
9
a second feed flow axis, which is in non-parallel relationship with the first
feed flow axis.
The flow of aqueous cementitious slurry is passed into a distribution conduit.
The
distribution conduit includes a distribution outlet extending a predetermined
distance
along a transverse axis, which is substantially perpendicular to the
longitudinal axis.
[0032] In another embodiment, a method of preparing a cementitious product
includes discharging a flow of aqueous cementitious slurry from a mixer. The
flow of
aqueous cementitious slurry is passed through an entry portion of a
distribution conduit
of a slurry distributor. The flow of aqueous cementitious slurry is discharged
from a
distribution outlet of the slurry distributor upon a web of cover sheet
material moving
along a machine direction. A wiper blade is reciprocally moved over a clearing
path
along a bottom surface of the distribution conduit between a first position
and a second
position to clear aqueous cementitious slurry therefrom. The clearing path is
disposed
adjacent the distribution outlet.
[0033] In still another embodiment, a method of preparing a cementitious
product
includes discharging a flow of aqueous cementitious slurry from a mixer. The
flow of
aqueous cementitious slurry is passed through an entry portion of a
distribution conduit
of a slurry distributor. The flow of aqueous cementitious slurry is discharged
from an
outlet opening of a distribution outlet of the slurry distributor upon a web
of cover sheet
material moving along a machine direction. The distribution outlet extends a
predetermined distance along a transverse axis, which is substantially
perpendicular to
the longitudinal axis. The outlet opening has a width, along the transverse
axis, and a
height, along a vertical axis mutually perpendicular to the longitudinal axis
and the
transverse axis. A portion of the distribution conduit adjacent the
distribution outlet is
compressively engaged to vary the shape and/or size of the outlet opening.
[0034] Embodiments of a mold for use in a method for making a slurry
distributor
according to principles of the present disclosure are also disclosed herein.
Embodiments of supports for a slurry distributor according to principles of
the present
disclosure are also disclosed herein.
[0035] Further and alternative aspects and features of the disclosed
principles will be
appreciated from the following detailed description and the accompanying
drawings. As
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
will be appreciated, the slurry distribution systems disclosed herein are
capable of being
carried out and used in other and different embodiments, and capable of being
modified
in various respects. Accordingly, it is to be understood that both the
foregoing general
description and the following detailed description are exemplary and
explanatory only
and do not restrict the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The patent or application file contains at least one drawing
executed in color.
Copies of this patent or patent application publication with color drawing(s)
will be
provided by the Office upon request and payment of the necessary fee.
[0037] FIG. 1 is a perspective view of an embodiment of a slurry
distributor
constructed in accordance with principles of the present disclosure.
[0038] FIG. 2 is a perspective view of the slurry distributor of FIG. 1 and
a
perspective view of an embodiment of a slurry distributor support constructed
in
accordance with principles of the present disclosure.
[0039] FIG. 3 is a front elevational view of the slurry distributor of FIG.
1 and the
slurry distributor support of FIG. 2.
[0040] FIG. 4 is a perspective view of an embodiment of a slurry
distributor
constructed in accordance with principles of the present disclosure that
defines an
interior geometry that is similar to the slurry distributor of FIG. 1, but
that is constructed
from a rigid material and has a two-piece construction.
[0041] FIG. 5 is another perspective view of the slurry distributor of FIG.
4 but with a
profiling system removed for illustrative purposes.
[0042] FIG. 6 is an isometric view of another embodiment of a slurry
distributor
constructed in accordance with principles of the present disclosure, which
includes a
first feed inlet and a second feed inlet disposed at about a sixty degree feed
angle with
respect to a longitudinal axis or machine direction of the slurry distributor.
[0043] FIG. 7 is a top plan view of the slurry distributor of FIG. 6.
[0044] FIG. 8 is a rear elevational view of the slurry distributor of FIG.
6.
[0045] FIG. 9 is a top plan view of a first piece of the slurry distributor
of FIG. 6,
which has a two-piece construction.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
11
[0046] FIG. 10 is a front perspective view of the slurry distributor piece
of FIG. 9.
[0047] FIG. ills an exploded view of the slurry distributor of FIG. 6 and a
support
system for the slurry distributor constructed in accordance with principles of
the present
disclosure.
[0048] FIG. 12 is a perspective view of the slurry distributor and the
support system
of FIG. 11.
[0049] FIG. 13 is an exploded view of the slurry distributor of FIG. 6 and
another
embodiment of a support system constructed in accordance with principles of
the
present disclosure.
[0050] FIG. 14 is a perspective view of the slurry distributor and the
support system
of FIG. 13.
[0051] FIG. 15 is a perspective view of an embodiment of a slurry
distributor
constructed in accordance with principles of the present disclosure that
defines an
interior geometry that is similar to the slurry distributor of FIG. 6, but
that is constructed
from a flexible material and has an integral construction.
[0052] FIG. 16 is a top plan view of the slurry distributor of FIG. 15.
[0053] FIG. 17 is an enlarged, perspective view of the interior geometry
defined by
the slurry distributor of FIG. 15, illustrating progressive cross-sectional
flow areas of a
portion of the feed conduit thereof.
[0054] FIG. 18 is an enlarged, perspective view of the interior geometry of
the slurry
distributor of FIG. 15, illustrating another progressive cross-sectional flow
area of the
feed conduit.
[0055] FIG. 19 is an enlarged, perspective view of the interior geometry of
the slurry
distributor of FIG. 15, illustrating yet another progressive cross-sectional
flow area of the
feed conduit which is aligned with a half of an entry portion to a
distribution conduit of
the slurry distributor of FIG. 15.
[0056] FIG. 20 is a perspective view of the slurry distributor of FIG. 15
and another
embodiment of a support system constructed in accordance with principles of
the
present disclosure.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
12
[0057] FIG. 21 is a perspective view as in FIG. 20, but with a support
frame removed
for illustrative purposes to show a plurality of retaining plates in
distributed relationship
with the slurry distributor of FIG. 15.
[0058] FIG. 22 is a front perspective view of another embodiment of a
slurry
distributor and another embodiment of a support system constructed in
accordance with
principles of the present disclosure.
[0059] FIG. 23 is a rear perspective view of the slurry distributor and the
support
system of FIG. 22.
[0060] FIG. 24 is a top plan view of the slurry distributor and the support
system of
FIG. 22.
[0061] FIG. 25 is a side elevational view of the slurry distributor and the
support
system of FIG. 22.
[0062] FIG. 26 is a front elevational view of the slurry distributor and
the support
system of FIG. 22.
[0063] FIG. 27 is a rear elevational view of the slurry distributor and the
support
system of FIG. 22.
[0064] FIG. 28 is an enlarged, detail view of a distal portion of the
slurry distributor,
illustrating an embodiment of a slurry wiping mechanism constructed in
accordance with
principles of the present disclosure.
[0065] FIG. 29 is a perspective view of a profiling mechanism constructed
in
accordance with principles of the present disclosure and used in the slurry
distributor of
FIG. 22.
[0066] FIG. 30 is a front elevational view of the profiling mechanism of
FIG. 29.
[0067] FIG. 30A is a view as in FIG. 30, illustrating a profiling member of
the profiling
mechanism in a compressed position.
[0068] FIG. 30B is a view as in FIG. 30, illustrating the profiling member
of the
profiling mechanism in a pivoted position.
[0069] FIG. 30C is an enlarged, detail exploded view of the profiling
member,
illustrating a connection technique between a translation rod and a profiling
segment.
[0070] FIG. 31 is a side elevational view of the profiling mechanism of
FIG. 29.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
13
[0071] FIG. 32 is a top plan view of the profiling mechanism of FIG. 29.
[0072] FIG. 33 is a bottom elevational view of the profiling mechanism of
FIG. 29.
[0073] FIG. 34 is a top plan view of the slurry distributor and the support
system of
FIG. 22 with a support frame removed for illustrative purposes.
[0074] FIG. 35 is an enlarged, detail view taken from the side of a bulb
portion of the
slurry distributor of FIG. 22.
[0075] FIG. 36 is a perspective view of a pair of rigid support inserts
resting upon a
bottom support member of the support system of FIG. 22.
[0076] FIG. 37 is a side elevational view of the rigid support insert of
FIG. 36.
[0077] FIG. 38 is a front elevational view of the rigid support insert of
FIG. 36.
[0078] FIG. 39 is a rear elevational view of the rigid support insert of
FIG. 36.
[0079] FIG. 40 is a front elevational view of the slurry distributor of
FIG. 22.
[0080] FIG. 41 is a rear elevational view of the slurry distributor of FIG.
22.
[0081] FIG. 42 is a bottom perspective view of the slurry distributor of
FIG. 22.
[0082] FIG. 43 is a bottom plan view of the slurry distributor of FIG. 22.
[0083] FIG. 44 is a top plan view of a half portion of the slurry
distributor of FIG. 22.
[0084] FIG. 45 is a cross-sectional view taken along line 45-45 in FIG. 44.
[0085] FIG. 46 is a cross-sectional view taken along line 46-46 in FIG. 44.
[0086] FIG. 47 is a cross-sectional view taken along line 47-47 in FIG. 44.
[0087] FIG. 48 is a cross-sectional view taken along line 48-48 in FIG. 44.
[0088] FIG. 49 is a cross-sectional view taken along line 49-49 in FIG. 44.
[0089] FIG. 50 is a cross-sectional view taken along line 50-50 in FIG. 44.
[0090] FIG. 51 is a cross-sectional view taken along line 51-51 in FIG. 44.
[0091] FIG. 52 is a cross-sectional view taken along line 52-52 in FIG. 44.
[0092] FIG. 53 is a cross-sectional view taken along line 53-53 in FIG. 44.
[0093] FIG. 54 is a perspective view of an embodiment of a multi-piece mold
for
making a slurry distributor as in FIG. 1 constructed in accordance with
principles of the
present disclosure.
[0094] FIG. 55 is a top plan view of the mold of FIG. 54.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
14
[0095] FIG. 56 is an exploded view of an embodiment of a multi-piece mold
for
making a slurry distributor as in FIG. 15 constructed in accordance with
principles of the
present disclosure.
[0096] FIG. 57 is a perspective view of another embodiment of a mold for
making a
piece of a two-piece slurry distributor constructed in accordance with
principles of the
present disclosure.
[0097] FIG. 58 is a top plan view of the mold of FIG. 57.
[0098] FIG. 59 is a schematic plan diagram of an embodiment of a gypsum
slurry
mixing and dispensing assembly including a slurry distributor in accordance
with
principles of the present disclosure.
[0099] FIG. 60 is a schematic plan diagram of another embodiment of a
gypsum
slurry mixing and dispensing assembly including a slurry distributor in
accordance with
principles of the present disclosure.
[00100] FIG. 61 is a schematic elevational diagram of an embodiment of a wet
end of
a gypsum wallboard manufacturing line in accordance with principles of the
present
disclosure.
[00101] FIG .62 is a perspective view of an embodiment of a flow splitter
constructed
in accordance with principles of the present disclosure suitable for use in a
gypsum
slurry mixing and dispensing assembly including a slurry distributor.
[00102] FIG. 63 is a side elevational view, in section, of the flow
splitter of FIG. 62.
[00103] FIG. 64 is a side elevational view of the flow splitter of FIG. 62
with an
embodiment of a squeezing apparatus constructed in accordance with principles
of the
present disclosure mounted thereto.
[00104] FIG. 65 is a top plan view of a half portion of a slurry
distributor similar to the
slurry distributor of FIG. 15.
[00105] FIG. 66 is a plot of the data from Table I of Example 1 showing the
dimensionless distance from the feed inlet versus the dimensionless area and
the
dimensionless hydraulic radius of the half portion of the slurry distributor
of FIG. 65.
[00106] FIG. 67 is a plot of the data from Tables II and III of Examples 2 and
3,
respectively, showing the dimensionless distance from the feed inlet versus
the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
dimensionless velocity of a flow of modeled slurry moving through the half
portion of the
slurry distributor of FIG. 65.
[00107] FIG. 68 is a plot of the data from Tables II and III of Examples 2
and 3,
respectively, showing the dimensionless distance from the feed inlet versus
the
dimensionless shear rate in the modeled slurry moving through the half portion
of the
slurry distributor of FIG. 65.
[00108] FIG. 69 is a plot of the data from Tables ll and III of Examples 2
and 3,
respectively, showing the dimensionless distance from the feed inlet versus
the
dimensionless viscosity of the modeled slurry moving through the half portion
of the
slurry distributor of FIG. 65.
[00109] FIG. 70 is a plot of the data from Tables II and III of Examples 2 and
3,
respectively, showing the dimensionless distance from the feed inlet versus
the
dimensionless shear stress in the modeled slurry moving through the half
portion of the
slurry distributor of FIG. 65.
[00110] FIG. 71 is a plot of the data from Tables II and III of Examples 2
and 3,
respectively, showing the dimensionless distance from the feed inlet versus
the
dimensionless Reynolds number of the modeled slurry moving through the half
portion
of the slurry distributor of FIG. 65.
[00111] FIG. 72 is a top plan view of a slurry distributor similar to the
slurry distributor
of FIG. 22.
[00112] FIG. 73 is a top perspective view of a computational fluid dynamics
(CFD)
model output for a half portion of the slurry distributor of FIG. 72.
[00113] FIG. 74 is a view as in FIG. 73, illustrating various regions
discussed in
Examples 4-6.
[00114] FIG. 75 is a view of the region A indicated in FIG. 74.
[00115] FIG. 76 is a top plan view of the region A illustrating radial
locations used to
conduct CFD analysis.
[00116] FIG. 77 is a plot of the data from Table IV of Example 4 showing the
radial
location at region A versus the dimensionless average velocity moving through
region A
of the half portion of the slurry distributor of FIG. 73.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
16
[00117] FIG. 78 is an enlarged, detail view taken from FIG. 72,
illustrating a region B
of the slurry distributor in which a flow of slurry moving therethrough has a
swirl motion.
[00118] FIG. 79 is a plot of the data from Table VI of Example 6 showing the
dimensionless distance from the feed inlet versus the dimensionless velocity
of a flow of
modeled slurry moving through the half portion of the slurry distributor of
FIG. 73.
[00119] FIG. 80 is a plot of the data from Table VI of Example 6 showing the
dimensionless distance from the feed inlet versus the dimensionless shear rate
in the
modeled slurry moving through the half portion of the slurry distributor of
FIG. 73.
[00120] FIG. 81 is a plot of the data from Table VI of Example 6 showing the
dimensionless distance from the feed inlet versus the dimensionless viscosity
of the
modeled slurry moving through the half portion of the slurry distributor of
FIG. 73.
[00121] FIG. 82 is a plot of the data from Table VI of Example 6 showing the
dimensionless distance from the feed inlet versus the dimensionless Reynolds
number
of the modeled slurry moving through the half portion of the slurry
distributor of FIG. 73.
[00122] FIG. 83 is a plot of the data from Table VII of Example 7 showing the
dimensionless distance along the width of the outlet opening from a central
transverse
midpoint versus the spread angle of the modeled slurry discharging from the
half portion
of the slurry distributor of FIG. 73.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[00123] The present disclosure provides various embodiments of a slurry
distribution
system that can be used in the manufacture of products, including cementitious
products such as gypsum wallboard, for example. Embodiments of a slurry
distributor
constructed in accordance with principles of the present disclosure can be
used in a
manufacturing process to effectively distribute a multi-phase slurry, such as
one
containing air and liquid phases, such as found in an aqueous foamed gypsum
slurry,
for example.
[00124] Embodiments of a distribution system constructed in accordance with
principles of the present disclosure can be used to distribute a slurry (e.g.,
an aqueous
calcined gypsum slurry) onto an advancing web (e.g., paper or mat) moving on a
conveyor during a continuous board (e.g., wallboard) manufacturing process. In
one
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
17
aspect, a slurry distribution system constructed in accordance with principles
of the
present disclosure can be used in a conventional gypsum drywall manufacturing
process as, or part of, a discharge conduit attached to a mixer adapted to
agitate
calcined gypsum and water to form an aqueous calcined gypsum slurry.
[00125] Embodiments of a slurry distribution system constructed in accordance
with
principles of the present disclosure are aimed at accomplishing wider
distribution (along
the cross-machine direction) of a uniform gypsum slurry. Embodiments of a
slurry
distribution system of the present disclosure are suitable for use with a
gypsum slurry
having a range of WSRs, including WSRs conventionally used to manufacture
gypsum
wallboard and those that are relatively lower and have a relatively higher
viscosity.
Furthermore, a gypsum slurry distribution system of the present disclosure can
be used
to help control air-liquid phase separation, such as, in aqueous foamed gypsum
slurry,
including foamed gypsum slurry having a very high foam volume. The spreading
of the
aqueous calcined gypsum slurry over the advancing web can be controlled by
routing
and distributing the slurry using a distribution system as shown and described
herein.
[00126] A cementitious slurry mixing and dispensing assembly according to
principles
of the present disclosure can be used to form any type of cementitious
product, such as
a board, for example. In some embodiments, a cementitious board, such as a
gypsum
drywall, a Portland cement board or an acoustical panel, for example, can be
formed.
[00127] The cementitious slurry can be any conventional cementitious slurry,
for
example any cementitious slurry commonly used to produce gypsum wallboard,
acoustical panels including, for example, acoustical panels described in U.S.
Patent
Application Publication No. 2004/0231916, or Portland cement board. As such,
the
cementitious slurry can optionally further comprise any additives commonly
used to
produce cementitious board products. Such additives include structural
additives
including mineral wool, continuous or chopped glass fibers (also referred to
as
fiberglass), perlite, clay, vermiculite, calcium carbonate, polyester, and
paper fiber, as
well as chemical additives such as foaming agents, fillers, accelerators,
sugar,
enhancing agents such as phosphates, phosphonates, borates and the like,
retarders,
binders (e.g., starch and latex), colorants, fungicides, biocides, hydrophobic
agent, such
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
18
as a silicone-based material (e.g., a silane, siloxane, or silicone-resin
matrix), and the
like. Examples of the use of some of these and other additives are described,
for
instance, in U.S. Patent Nos. 6,342,284; 6,632,550; 6,800,131; 5,643,510;
5,714,001;
and 6,774,146; and U.S. Patent Application Publication Nos. 2004/0231916;
2002/0045074; 2005/0019618; 2006/0035112; and 2007/0022913.
[00128] Non-limiting examples of cementitious materials include Portland
cement,
sorrel cement, slag cement, fly ash cement, calcium alumina cement, water-
soluble
calcium sulfate anhydrite, calcium sulfate a-hemihydrate, calcium sulfate
hem ihyd rate, natural, synthetic or chemically modified calcium sulfate
hemihydrate,
calcium sulfate dihydrate ("gypsum," "set gypsum," or "hydrated gypsum"), and
mixtures
thereof. In one aspect, the cementitious material desirably comprises calcined
gypsum,
such as in the form of calcium sulfate alpha hemihydrate, calcium sulfate beta
hemihydrate, and/or calcium sulfate anhydrite. In embodiments, the calcined
gypsum
can be fibrous in some embodiments and nonfibrous in others. The calcined
gypsum
can include at least about 50% beta calcium sulfate hemihydrate. In other
embodiments, the calcined gypsum can include at least about 86% beta calcium
sulfate
hemihydrate. The weight ratio of water to calcined gypsum can be any suitable
ratio,
although, as one of ordinary skill in the art will appreciate, lower ratios
can be more
efficient because less excess water must be driven off during manufacture,
thereby
conserving energy. In some embodiments, the cementitious slurry can be
prepared by
combining water and calcined gypsum in a range from about a 1:6 ratio by
weight
respectively to about 1:1 ratio, such as about 2:3, for board production
depending on
products.
[00129] Embodiments of a method of preparing a cementitious product, such as a
gypsum product, in accordance with principles of the present disclosure can
include
distributing an aqueous calcined gypsum slurry upon an advancing web using a
slurry
distributor constructed in accordance with principles of the present
disclosure. Various
embodiments of a method of distributing an aqueous calcined gypsum slurry upon
a
moving web are described herein.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
19
[00130] Turning now to the Figures, there is shown in FIGS. 1-3 an embodiment
of a
slurry distributor 120 according to principles of the present disclosure, and
in FIGS. 4
and 5, another embodiment of a slurry distributor 220 according to principles
of the
present disclosure is shown. The slurry distributor 120 shown in FIGS. 1-3 is
constructed from a resiliently flexible material, whereas the slurry
distributor 220 shown
in FIGS. 3 and 4 is made from a relatively rigid material. However, the
interior flow
geometry of both slurry distributors 120, 220 in FIGS. 1-5 is the same, and
reference
should also be made to FIG. 5 when considering the slurry distributor 120 of
FIGS. 1-3.
[00131]
Referring to FIG. 1, the slurry distributor 120 includes a feed conduit 122,
which has first and second feed inlets 124, 125, and a distribution conduit
128, which
includes a distribution outlet 130 and is in fluid communication with the feed
conduit
128. A profiling system 132 (see FIG. 3) adapted to locally vary the size of
the
distribution outlet 130 of the distribution conduit 128 can also be provided.
[00132] Referring to FIG. 1, the feed conduit 122 extends generally along a
transverse axis or cross-machine direction 60, which is substantially
perpendicular to a
longitudinal axis or machine direction 50. The first feed inlet 124 is in
spaced
relationship with the second feed inlet 125. The first feed inlet 124 and the
second feed
inlet 125 define respective openings 134, 135 that have substantially the same
area.
The illustrated openings 134, 135 of the first and second feed inlets 124, 125
both have
a circular cross-sectional shape as illustrated in this example. In other
embodiments,
the cross-sectional shape of the feed inlets 124, 125 can take other forms,
depending
upon the intended applications and process conditions present.
[00133] The first and second feed inlets 124, 125 are in opposing relationship
to each
other along the cross-machine axis 60 such that the first and second feed
inlets 124,
125 are disposed at substantially a 90 angle to the machine axis 50. In other
embodiments the first and second feed inlets 124, 125 can be oriented in a
different
manner with respect to the machine direction. For example, in some
embodiments, the
first and second feed inlets 124, 125 can be at an angle between 0 and about
135 with
respect to the machine direction 50.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
[00134] The feed conduit 122 includes first and second entry segments 136, 137
and
a bifurcated connector segment 139 disposed between the first and second entry
segments 136, 137. The first and second entry segments 136, 137 are generally
cylindrical and extend along the transverse axis 60 such that they are
substantially
parallel to a plane 57 defined by the longitudinal axis 50 and the transverse
axis 60.
The first and second feed inlets 124, 125 are disposed at the distal ends of
the first and
the second entry segments 136, 137, respectively, and are in fluid
communication
therewith.
[00135] In other embodiments the first and second feed inlets 124, 125 and the
first
and second entry segments 136, 137 can be oriented in a different manner with
respect
to the transverse axis 60, the machine direction 50, and/or the plane 57
defined by the
longitudinal axis 50 and the transverse axis 60. For example, in some
embodiments,
the first and second feed inlets 124, 125 and the first and second entry
segments 136,
137 can each be disposed substantially in the plane 57 defined by the
longitudinal axis
50 and the transverse axis 60 at a feed angle 6 with respect to the
longitudinal axis or
machine direction 50 which is an angle in a range up to about 1350 with
respect to the
machine direction 50, and in other embodiments in a range from about 30 to
about
135 , and in yet other embodiments in a range from about 45 to about 135 ,
and in still
other embodiments in a range from about 40 to about 110 .
[00136] The bifurcated connector segment 139 is in fluid communication with
the first
and second feed inlets 124, 125 and the first and the second entry segments
136, 137.
The bifurcated connector segment 139 includes first and second shaped ducts
141,
143. The first and second feed inlets 124, 125 of the feed conduit 22 are in
fluid
communication with the first and second shaped ducts 141, 143, respectively.
The first
and second shaped ducts 141, 143 of the connector segment 139 are adapted to
receive a first flow in a first feed direction 190 and a second flow in a
second flow
direction 191 of aqueous calcined gypsum slurry from the first and second feed
inlets
124, 125, respectively, and to direct the first and second flows 190, 191 of
aqueous
calcined gypsum slurry into the distribution conduit 128.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
21
[00137] As shown in FIG. 5, the first and second shaped ducts 141, 143 of the
connector segment 139 define first and second feed outlets 140, 145
respectively in
fluid communication with the first and second feed inlets 124, 125. Each feed
outlet
140, 145 is in fluid communication with the distribution conduit 128. Each of
the
illustrated first and second feed outlets 140, 145 defines an opening 142 with
a
generally rectangular inner portion 147 and a substantially circular side
portion 149.
The circular side portions 145 are disposed adjacent side walls 151, 153 of
the
distribution conduit 128.
[00138] In embodiments, the openings 142 of the first and second feed outlets
140,
145 can have a cross-sectional area that is larger than the cross-sectional
area of the
openings 134, 135 of the first feed inlet 124 and the second feed inlet 125,
respectively.
For example, in some embodiments, the cross-sectional area of the openings 142
of the
first and second feed outlets 140, 145 can be in a range from greater than to
about
300% greater than the cross-sectional area of the openings 134, 135 of the
first feed
inlet 124 and the second feed inlet 125, respectively, in a range from greater
than to
about 200% greater in other embodiments, and in a range from greater than to
about
150% greater in still other embodiments.
[00139] In embodiments, the openings 142 of the first and second feed outlets
140,
145 can have a hydraulic diameter (4 x cross-sectional area / perimeter) that
is smaller
than the hydraulic diameter of the openings 134, 135 of the first feed inlet
124 and the
second feed inlet 125, respectively. For example, in some embodiments, the
hydraulic
diameter of the openings 142 of the first and second feed outlets 140, 145 can
be about
80% or less than the hydraulic diameter of the openings 134, 135 of the first
feed inlet
124 and the second feed inlet 125, respectively, about 70% or less in other
embodiments, and about 50% or less in still other embodiments
[00140] Referring back to FIG. 1, the connector segment 139 is
substantially parallel
to the plane 57 defined by the longitudinal axis 50 and the transverse axis
60. In other
embodiments the connector segment 139 can be oriented in a different manner
with
respect to the transverse axis 60, the machine direction 50, and/or the plane
57 defined
by the longitudinal axis 50 and the transverse axis 60.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
22
[00141] The first feed inlet 124, the first entry segment 136, and the first
shaped duct
141 are a mirror image of the second feed inlet 125, the second entry segment
137, and
the second shaped duct 143, respectively. Accordingly, it will be understood
that the
description of one feed inlet is applicable to the other feed inlet, the
description of one
entry segment is applicable to the other entry segment, and the description of
one
shaped duct is applicable to the other shaped duct, as well in a corresponding
manner.
[001421 The first shaped duct 141 is fluidly connected to the first feed inlet
124 and
the first entry segment 136. The first shaped duct 141 is also fluidly
connected to the
distribution conduit 128 to thereby help fluidly connect the first feed inlet
124 and the
distribution outlet 130 such that the first flow 190 of slurry can enter the
first feed inlet
124; travel through the first entry segment 136, the first shaped duct 141,
and the
distribution conduit 128; and be discharged from the slurry distributor 120
through the
distribution outlet 130.
[00143] The first shaped duct 141 has a front, outer curved wall 157 and an
opposing
rear, inner curved wall 158 defining a curved guide surface 165 adapted to
redirect the
first flow of slurry from the first feed flow direction 190, which is
substantially parallel to
the transverse or cross-machine direction 60, to an outlet flow direction 192,
which is
substantially parallel to the longitudinal axis or machine direction 50 and
substantially
perpendicular to the first feed flow direction 190. The first shaped duct 141
is adapted
to receive the first flow of slurry moving in the first feed flow direction
190 and redirect
the slurry flow direction by a change in direction angle a, as shown in FIG.
9, such that
the first flow of slurry is conveyed into the distribution conduit 128 moving
substantially
in the outlet flow direction 192.
[00144] In use, the first flow of aqueous calcined gypsum slurry passes
through the
first feed inlet 124 in the first feed direction 190, and the second flow of
aqueous
calcined gypsum slurry passes through the second feed inlet 125 in the second
feed
direction 191. The first and second feed directions 190, 191 can be
symmetrical with
respect to each other along the longitudinal axis 50 in some embodiments. The
first
flow of slurry moving in the first feed flow direction 190 is redirected in
the slurry
distributor 120 through a change in direction angle a in a range up to about
135 to the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
23
outlet flow direction 192. The second flow of slurry moving in the second feed
flow
direction 191 is redirected in the slurry distributor 120 through a change in
direction
angle a in a range up to about 1350 to the outlet flow direction 192. The
combined first
and second flows 190, 191 of aqueous calcined gypsum slurry discharge from the
slurry
distributor 120 moving generally in the outlet flow direction 192. The outlet
flow
direction 192 can be substantially parallel to the longitudinal axis or
machine direction
50.
1001451 For example, in the illustrated embodiment, the first flow of
slurry is redirected
from the first feed flow direction 190 along the cross-machine direction 60
through a
change in direction angle a of about ninety degrees about the vertical axis 55
to the
outlet flow direction 192 along the machine direction 50. In some embodiments,
the
flow of slurry can be redirected from a first feed flow direction 190 through
a change in
direction angle a about the vertical axis 55 which is in a range up to about
135 to the
outlet flow direction 192, and in other embodiments in a range from about 30
to about
135 , and in yet other embodiments in a range from about 45 to about 135 ,
and in still
other embodiments in a range from about 40 to about 110 .
1001461 In some embodiments, the shape of the rear curved guide surface 165
can be
generally parabolic, which in the illustrated embodiment can be defined by a
parabola of
the form Ax2+B. In alternate embodiments, higher order curves may be used to
define
the rear curved guide surface 165 or, alternatively, the rear, inner wall 158
can have a
generally curved shape that is made up of straight or linear segments that
have been
oriented at their ends to collectively define a generally curved wall.
Moreover, the
parameters used to define the specific shape factors of the outer wall can
depend on
specific operating parameters of the process in which the slurry distributor
will be used.
[00147] At least one of the feed conduit 122 and the distribution conduit 128
can
include an area of expansion having a cross-sectional flow area that is
greater than a
cross-sectional flow area of an adjacent area upstream from the area of
expansion in a
direction from the feed conduit 122 toward the distribution conduit 128. The
first entry
segment 136 and/or the first shaped duct 141 can have a cross section that
varies
along the direction of flow to help distribute the first flow of slurry moving
therethrough.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
24
The shaped duct 141 can have a cross sectional flow area that increases in a
first flow
direction 195 from the first feed inlet 124 toward the distribution conduit
128 such that
the first flow of slurry is decelerated as it passes through the first shaped
duct 141. In
some embodiments, the first shaped duct 141 can have a maximum cross-section
flow
area at a predetermined point along the first flow direction 195 and decrease
from the
maximum cross-sectional flow area at points further along the first flow
direction 195.
[00148] In some embodiments, the maximum cross-sectional flow area of the
first
shaped duct 141 is about 200% of the cross-sectional area of the opening 134
of the
first feed inlet 124 or less. In yet other embodiments, the maximum cross-
sectional flow
area of the shaped duct 141 is about 150% of the cross-sectional area of the
opening
134 of the first feed inlet 124 or less. In still other embodiments, the
maximum cross-
sectional flow area of the shaped duct 141 is about 125% of the cross-
sectional area of
the opening 134 of the first feed inlet 124 or less. In yet other embodiments,
the
maximum cross-sectional flow area of the shaped duct 141 is about 110% of the
cross-
sectional area of the opening 134 of the first feed inlet 124 or less. In some
embodiments, the cross-sectional flow area is controlled such that the flow
area does
not vary more than a predetermined amount over a given length to help prevent
large
variations in the flow regime.
[00149] In some embodiments, the first entry segment 136 and/or the first
shaped
duct 141 can include one or more guide channels 167, 168 that are adapted to
help
distribute the first flow of slurry toward the outer and/or the inner walls
157, 158 of the
feed conduit 122. The guide channels 167, 168 are adapted to increase the flow
of
slurry around the boundary wall layers of the slurry distributor 120.
[00150] Referring to FIGS. 1 and 5, the guide channels 167, 168 can be
configured to
have a larger cross-sectional area than an adjacent portion 171 of the feed
conduit 122
which defines a restriction that promotes flow to the adjacent guide channel
167, 168
respectively disposed at the wall region of the slurry distributor 120. In the
illustrated
embodiment, the feed conduit 122 includes the outer guide channel 167 adjacent
the
outer wall 157 and the sidewall 151 of the distribution conduit 128 and the
inner guide
channel 168 adjacent the inner wall 158 of the first shaped duct 141. The
cross-
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
sectional areas of the outer and inner guide channels 167, 168 can become
progressively smaller moving in the first flow direction 195. The outer guide
channel
167 can extend substantially along the sidewall 151 of the distribution
conduit 128 to the
distribution outlet 130. At a given cross-sectional location through the first
shaped duct
141 in a direction perpendicular to the first flow direction 195, the outer
guide channel
167 has a larger cross-sectional area than the inner guide channel 168 to help
divert the
first flow of slurry from its initial line of movement in the first feed
direction 190 toward
the outer wall 157.
[00151] Providing guide channels adjacent wall regions can help direct or
guide slurry
flow to those regions, which can be areas in conventional systems where "dead
spots"
of low slurry flow are found. By encouraging slurry flow at the wall regions
of the slurry
distributor 120 through the provision of guide channels, slurry buildup inside
the slurry
distributor is discouraged and the cleanliness of the interior of the slurry
distributor 120
can be enhanced. The frequency of slurry buildup breaking off into lumps which
can
tear the moving web of cover sheet material can also be decreased.
[00152] In other embodiments, the relative sizes of the outer and inner guide
channels
167, 168 can be varied to help adjust the slurry flow to improve flow
stability and reduce
the occurrence of air-liquid slurry phase separation. For example, in
applications using
a slurry that is relatively more viscous, at a given cross-sectional location
through the
first shaped duct 141 in a direction perpendicular to the first flow direction
195, the outer
guide channel 167 can have a smaller cross-sectional area than the inner guide
channel
168 to help urge the first flow of slurry toward the inner wall 158.
[00153] The inner curved walls 158 of the first and second shaped ducts 141,
142
meet to define a peak 175 adjacent an entry portion 152 of the distribution
conduit 128.
The peak 175 effectively bifurcates the connector segment 139. Each feed
outlet 140,
145 is in fluid communication with the entry portion 152 of the distribution
conduit 128.
[00154] The location of the peak 175 along the longitudinal axis 50 can vary
in other
embodiments. For example, the inner curved walls 158 of the first and second
shaped
ducts 141, 142 can be less curved in other embodiments such that the peak 175
is
further away from the distribution outlet 130 along the longitudinal axis 50
than as
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
26
shown in the illustrated slurry distributor 120. In other embodiments, the
peak 175 can
be closer to the distribution outlet 130 along the longitudinal axis 50 than
as shown in
the illustrated slurry distributor 120.
1001551 The distribution conduit 128 is substantially parallel to the plane 57
defined by
the longitudinal axis 50 and the transverse axis 60 and is adapted to urge the
combined
first and second flows of aqueous calcined gypsum slurry from the first and
second
shaped ducts 141, 142 into a generally two-dimensional flow pattern for
enhanced
stability and uniformity. The distribution outlet 130 has a width that extends
a
predetermined distance along the transverse axis 60 and a height that extends
along a
vertical axis 55, which is mutually perpendicular to the longitudinal axis 50
and the
transverse axis 60. The height of the distribution outlet 130 is small
relative to its width.
The distribution conduit 128 can be oriented relative to a moving web of cover
sheet
upon a forming table such that the distribution conduit 128 is substantially
parallel to the
moving web.
[00156] The distribution conduit 128 extends generally along the longitudinal
axis 50
and includes the entry portion 152 and the distribution outlet 130. The entry
portion 152
is in fluid communication with the first and second feed inlets 124, 125 of
the feed
conduit 122. Referring to FIG. 5, the entry portion 152 is adapted to receive
both the
first and the second flows of aqueous calcined gypsum slurry from the first
and second
feed inlets 124, 125 of the feed conduit 122. The entry portion 152 of the
distribution
conduit 128 includes a distribution inlet 154 in fluid communication with the
first and
second feed outlets 140, 145 of the feed conduit 122. The illustrated
distribution inlet
154 defines an opening 156 that substantially corresponds to the openings 142
of the
first and second feed outlets 140, 145. The first and second flows of aqueous
calcined
gypsum slurry combine in the distribution conduit 128 such that the combined
flows
move generally in the outlet flow direction 192 which can be substantially
aligned with
the line of movement of a web of cover sheet material moving over a forming
table in a
wallboard manufacturing line.
1001571 The distribution outlet 130 is in fluid communication with the entry
portion 152
and thus the first and second feed inlets 124, 125 and the first and second
feed outlets
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
27
140, 145 of the feed conduit 122. The distribution outlet 130 is in fluid
communication
with the first and second shaped ducts 141, 143 and is adapted to discharge
the
combined first and second flows of slurry therefrom along the outlet flow
direction 192
upon a web of cover sheet material advancing along the machine direction 50.
[00158] Referring to FIG. 1, the illustrated distribution outlet 130
defines a generally
rectangular opening 181 with semi-circular narrow ends 183, 185. The semi-
circular
ends 183, 185 of the opening 181 of the distribution outlet 130 can be the
terminating
end of the outer guide channels 167 disposed adjacent the side walls 151, 153
of the
distribution conduit 128.
[00159] The opening 181 of the distribution outlet 130 has an area which is
greater
than the sum of the areas of the openings 134, 135 of the first and second
feed inlets
124, 125 and is smaller than the area of the sum of the openings 142 of the
first and
second feed outlets 140, 145 (i.e., the opening 156 of the distribution inlet
154).
Accordingly, the cross-sectional area of the opening 156 of the entry portion
152 of the
distribution conduit 128 is greater than the cross-sectional area of the
opening 181 of
the distribution outlet 130.
[00160] For example, in some embodiments, the cross-sectional area of the
opening
181 of the distribution outlet 130 can be in a range from greater than to
about 400%
greater than the sum of the cross-sectional areas of the openings 134, 135 of
the first
and second feed inlets 124, 125, in a range from greater than to about 200%
greater in
other embodiments, and in a range from greater than to about 150% greater in
still other
embodiments. In other embodiments, the ratio of the sum of the cross-sectional
areas
of the openings 134, 135 of the first and second feed inlets 124, 125 to the
cross-
sectional area of the opening 181 of the distribution outlet 130 can be varied
based
upon one or more factors, including the speed of the manufacturing line, the
viscosity of
the slurry being distributed by the distributor 120, the width of the board
product being
made with the distributor 120, etc. In some embodiments, the cross-sectional
area of
the opening 156 of the entry portion 152 of the distribution conduit 128 can
be in a
range from greater than to about 200% greater than the cross-sectional area of
the
opening 181 of the distribution outlet 130, in a range from greater than to
about 150%
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
28
greater in other embodiments, and in a range from greater than to about 125%
greater
in still other embodiments.
1001611 The distribution outlet 130 extends substantially along the transverse
axis 60.
The opening 181 of the distribution outlet 130 has a width W1 of about twenty-
four
inches along the transverse axis 60 and a height H1 of about one inch along
the vertical
axis 55 (see FIG. 3, also). In other embodiments, the size and shape of the
opening
181 of the distribution outlet 130 can be varied.
100162] The distribution outlet 130 is disposed intermediately along the
transverse
axis 60 between the first feed inlet 124 and the second feed inlet 125 such
that the first
feed inlet 124 and the second feed inlet 125 are disposed substantially the
same
distance D1, D2 from a transverse central midpoint 187 of the distribution
outlet 130 (see
FIG. 3, also). The distribution outlet 130 can be made from a resiliently
flexible material
such that its shape is adapted to be variable along the transverse axis 60,
such as by
the profiling system 32, for example.
[00163] It is contemplated that the width W1 and/or height H1 of the opening
181 of the
distribution outlet 130 can be varied in other embodiments for different
operating
conditions. In general, the overall dimensions of the various embodiments for
slurry
distributors as disclosed herein can be scaled up or down depending on the
type of
product being manufactured (for example, the thickness and/or width of
manufactured
product), the speed of the manufacturing line being used, the rate of
deposition of the
slurry through the distributor, the viscosity of the slurry, and the like. For
example, the
width W1, along the transverse axis 60, of the distribution outlet 130 for use
in a
wallboard manufacturing process, which conventionally is provided in nominal
widths no
greater than fifty-four inches, can be within a range from about eight to
about fifty-four
inches in some embodiments, and in other embodiments within a range from about
eighteen inches to about thirty inches. In other embodiments, the ratio of the
width W1,
along the transverse axis 60, of the distribution outlet 130 to the maximum
nominal
width of the panel being produced on the manufacturing system using the slurry
distributor constructed according to principles of the present disclosure can
be in a
range from about 1/7 to about 1, in a range from about 1/3 to about 1 in other
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
29
embodiments, in a range from about 1/3 to about 2/3 in yet other embodiments,
and in a
range from about 1/2 to about 1 in still other embodiments.
[00164] The height of the distribution outlet can be within a range from about
3/16
inch to about two inches in some embodiments, and in other embodiments between
about 3/16 inch and about an inch. In some embodiments including a rectangular
distribution outlet, the ratio of the rectangular width to the rectangular
height of the outlet
opening can be about 4 or more, in other embodiments about 8 or more, in some
embodiments from about 4 to about 288, in other embodiments from about 9 to
about
288, in other embodiments from about 18 to about 288, and in still other
embodiments
from about 18 to about 160.
[00165] The distribution conduit 128 includes a converging portion 182 in
fluid
communication with the entry portion 152. The height of the converging portion
182 is
less than the height at the maximum cross-sectional flow area of the first and
second
shaped ducts 141, 143 and less than the height of the opening 181 of the
distribution
outlet 130. In some embodiments, the height of the converging portion 182 can
be
about half the height of the opening 181 of the distribution outlet 130.
[00166] The converging portion 182 and the height of the distribution outlet
130 can
cooperate together to help control the average velocity of the combined first
and second
flows of aqueous calcined gypsum being distributed from the distribution
conduit 128.
The height and/or width of the distribution outlet 130 can be varied to adjust
the average
velocity of the combined first and second flows of slurry discharging from the
slurry
distributor 120.
[00167] In some embodiments, the outlet flow direction 192 is substantially
parallel to
the plane 57 defined by the machine direction 50 and the transverse cross-
machine
direction 60 of the system transporting the advancing web of cover sheet
material. In
other embodiments, the first and second feed directions 190, 191 and the
outlet flow
direction 192 are all substantially parallel to the plane 57 defined by the
machine
direction 50 and the transverse cross-machine direction 60 of the system
transporting
the advancing web of cover sheet material. In some embodiments, the slurry
distributor
can be adapted and arranged with respect to the forming table such that the
flow of
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
slurry is redirected in the slurry distributor 120 from the first and second
feed directions
190, 191 to the outlet flow direction 192 without undergoing substantial flow
redirection
by rotating about the cross-machine direction 60.
[00168] In some embodiments, the slurry distributor can be adapted and
arranged
with respect to the forming table such that the first and second flows of
slurry are
redirected in the slurry distributor from the first and second feed directions
190, 191 to
the outlet flow direction 192 by redirecting the first and second flows of
slurry by rotating
about the cross-machine direction 60 over an angle of about forty-five degrees
or less.
Such a rotation can be accomplished in some embodiments by adapting the slurry
distributor such that the first and second feed inlets 124, 125 and the first
and second
feed directions 190, 191 of the first and second flows of slurry are disposed
at a vertical
offset angle w with respect to the vertical axis 55 and the plane 57 formed by
the
machine axis 50 and the cross-machine axis 60. In embodiments, the first and
second
feed inlets 124, 125 and the first and second feed directions 190, 191 of the
first and
second flows of slurry can be disposed at a vertical offset angle w within a
range from
zero to about sixty degrees such that the flow of slurry is redirected about
the machine
axis 50 and moves along the vertical axis 55 in the slurry distributor 120
from the first
and second feed directions 190, 191 to the outlet flow direction 192. In
embodiments,
at least one of the respective entry segment 136, 137 and the shaped ducts
141, 143
can be adapted to facilitate the redirection of the slurry about the machine
axis 50 and
along the vertical axis 55. In embodiments, the first and second flows of
slurry can be
redirected from the first and second feed directions 190, 191 through a change
in
direction angle a about an axis substantially perpendicular to vertical offset
angle w
and/or one or more other rotational axes within a range of about forty-five
degrees to
about one hundred fifty degrees to the outlet flow direction 192 such that the
outlet flow
direction 192 is generally aligned with the machine direction 50.
1001691 In use, first and second flows of aqueous calcined gypsum slurry pass
through the first and second feed inlets 124, 125 in converging first and
second feed
directions 190, 191. The first and second shaped ducts 141, 143 redirect the
first and
second flows of slurry from the first feed direction 190 and the second feed
direction
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
31
191 so that the first and second flows of slurry move over a change in
direction angle a
from both being substantially parallel to the transverse axis 60 to both being
substantially parallel to the machine direction 50. The distribution conduit
128 can be
positioned such that it extends along the longitudinal axis 50 which
substantially
coincides with the machine direction 50 along which a web of cover sheet
material
moves in a method making a gypsum board. The first and second flows of aqueous
calcined gypsum slurry combine in the slurry distributor 120 such that the
combined first
and second flows of aqueous calcined gypsum slurry pass through the
distribution outlet
130 in the outlet flow direction 192 generally along the longitudinal axis 50
and in the
direction of the machine direction.
[00170] Referring to FIG. 2, a slurry distributor support 100 can be
provided to help
support the slurry distributor 120, which in the illustrated embodiment is
made from a
flexible material, such as PVC or urethane, for example. The slurry
distributor support
100 can be made from a suitable rigid material to help support the flexible
slurry
distributor 120. The slurry distributor support 100 can include a two-piece
construction.
The two pieces 101, 103 can be pivotally movable with respect to each other
about a
hinge 105 at the rear end thereof to allow for ready access to an interior 107
of the
support 100. The interior 107 of the support 100 can be configured such that
the
interior 107 substantially conforms to the exterior of the slurry distributor
120 to help
limit the amount of movement the slurry distributor 120 can undergo with
respect to the
support 100 and/or to help define the interior geometry of the slurry
distributor 120
through which a slurry will flow.
[00171] Referring to FIG. 3, in some embodiments, the slurry distributor
support 100
can be made from a suitable resiliently flexible material that provides
support and is
able to be deformed in response to the profiling system 132 mounted to the
support
100. The profiling system 132 can be mounted to the support 100 adjacent the
distribution outlet 130 of the slurry distributor 120. The profiling system
132 so installed
can act to vary the size and/or shape of the distribution outlet 130 of the
distribution
conduit 128 by also varying the size and/or shape of the closely conforming
support
100, which in turn, influences the size and/or shape of the distribution
outlet 130.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
32
[00172] Referring to FIG. 3, the profiling system 132 can be adapted to
selectively
change the size and/or shape of the opening 181 of the distribution outlet
130. In some
embodiments, the profiling system can be used to selectively adjust the height
H1 of the
opening 181 of the distribution outlet 130.
[00173] The illustrated profiling system 132 includes a plate 90, a plurality
of mounting
bolts 92 securing the plate to the distribution conduit 128, and a series of
adjustment
bolts 94, 95 threadingly secured thereto. The mounting bolts 92 are used to
secure the
plate 90 to the support 100 adjacent the distribution outlet 130 of the slurry
distributor
120. The plate 90 extends substantially along the transverse axis 60. In the
illustrated
embodiment, the plate 90 is in the form of a length of angle iron. In other
embodiments,
the plate 90 can have different shapes and can comprise different materials.
In still
other embodiments, the profiling system can include other components adapted
to
selectively change the size and/or shape of the opening 181 of the
distribution outlet
130.
[00174] The illustrated profiling system 132 is adapted to locally vary along
the
transverse axis 60 the size and/or shape of the opening 181 of the
distribution outlet
130. The adjustment bolts 94, 95 are in regular, spaced relationship to each
other
along the transverse axis 60 over the distribution outlet 130. The adjustment
bolts 94,
95 are independently adjustable to locally vary the size and/or shape of the
distribution
outlet 130.
[00175] The profiling system 132 can be used to locally vary the distribution
outlet 130
so as to alter the flow pattern of the combined first and second flows of
aqueous
calcined gypsum slurry being distributed from the slurry distributor 120. For
example,
the mid-line adjustment bolt 95 can be tightened down to constrict the
transverse central
midpoint 187 of the distribution outlet 130 to increase the edge flow angle
away from the
longitudinal axis 50 to facilitate spreading in the cross-machine direction 60
and to
improve the slurry flow uniformity in the cross-machine direction 60.
[00176] The profiling system 132 can be used to vary the size of the
distribution outlet
130 along the transverse axis 60 and maintain the distribution outlet 130 in
the new
shape. The plate 90 can be made from a material that is suitably strong such
that the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
33
plate 90 can withstand opposing forces exerted by the adjustment bolts 94, 95
in
response to adjustments made by the adjustment bolts 94, 95 in urging the
distribution
outlet 130 into a new shape. The profiling system 132 can be used to help even
out
variations in the flow profile of the slurry (for example, as a result of
different slurry
densities and/or different feed inlet velocities) being discharged from the
distribution
outlet 130 such that the exit pattern of the slurry from the distribution
conduit 128 is
more uniform.
100177] In other embodiments, the number of adjustment bolts can be varied
such
that the spacing between adjacent adjustment bolts changes. In other
embodiments,
such as where the width W1 of the distribution outlet 130 is different, the
number of
adjustment bolts can also be varied to achieve a desired adjacent bolt
spacing. In yet
other embodiments, the spacing between adjacent bolts can vary along the
transverse
axis 60, for example to provide greater locally-varying control at the side
edges 183,
185 of the distribution outlet 130.
[00178] A slurry distributor constructed in accordance with principles of the
present
disclosure can comprise any suitable material. In some embodiments, a slurry
distributor can comprise any suitable substantially rigid material which can
include a
suitable material which can allow the size and shape of the outlet to be
modified using a
profile system, for example. For example, a suitably rigid plastic, such as
ultra-high
molecular weight (UHMW) plastic, or metal can be used. In other embodiments, a
slurry distributor constructed in accordance with principles of the present
disclosure can
be made from a flexible material, such as a suitable flexible plastic
material, including
poly vinyl chloride (PVC) or urethane, for example. In some embodiments, a
slurry
distributor constructed in accordance with principles of the present
disclosure can
include a single feed inlet, entry segment, and shaped duct which is in fluid
communication with a distribution conduit.
[00179] A gypsum slurry distributor constructed in accordance with principles
of the
present disclosure can be used to help provide a wide cross machine
distribution of
aqueous calcined gypsum slurry to facilitate the spreading of high
viscous/lower WSR
gypsum slurries on a web of cover sheet material moving over a forming table.
The
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
34
gypsum slurry distribution system can be used to help control air-slurry phase
separation, as well.
[00180] In accordance with another aspect of the present disclosure, a gypsum
slurry
mixing and dispensing assembly can include a slurry distributor constructed in
accordance with principles of the present disclosure. The slurry distributor
can be
placed in fluid communication with a gypsum slurry mixer adapted to agitate
water and
calcined gypsum to form an aqueous calcined gypsum slurry. In one embodiment,
the
slurry distributor is adapted to receive a first flow and a second flow of
aqueous calcined
gypsum slurry from the gypsum slurry mixer and distribute the first and second
flows of
aqueous calcined gypsum slurry onto an advancing web.
[00181] The slurry distributor can comprise a part of, or act as, a discharge
conduit of
a conventional gypsum slurry mixer (e.g., a pin mixer) as is known in the art.
The slurry
distributor can be used with components of a conventional discharge conduit.
For
example, the slurry distributor can be used with components of a gate-canister-
boot
arrangement as known in the art or of the discharge conduit arrangements
described in
U.S. Patent Nos. 6,494,609; 6,874,930; 7,007,914; and 7,296,919.
[00182] A slurry distributor constructed in accordance with principles of the
present
disclosure can advantageously be configured as a retrofit in an existing
wallboard
manufacturing system. The slurry distributor preferably can be used to replace
a
conventional single or multiple-branch boot used in conventional discharge
conduits.
This gypsum slurry distributor can be retrofitted to an existing slurry
discharge conduit
arrangement, such as that shown in U.S. Patent No. 6,874,930 or 7,007,914, for
example, as a replacement for the distal dispensing spout or boot. However, in
some
embodiments, the slurry distributor may, alternatively, be attached to one or
more boot
outlet(s).
[00183] Referring to FIGS. 4 and 5, the slurry distributor 220 is similar
to the slurry
distributor 120 of FIGS. 1-3, except that it is constructed from a
substantially rigid
material. The interior geometry 207 of the slurry distributor 220 of FIGS. 4
and 5 is
similar to that of the slurry distributor 120 of FIGS. 1-3, and like reference
numerals are
used to indicate like structure. The interior geometry 207 of the slurry
distributor 207 is
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
adapted to define a flow path for the gypsum slurry traveling therethrough
which is of
the manner of a streamline flow, undergoing reduced or substantially no air-
liquid slurry
phase separation and substantially without undergoing a vortex flow path.
[00184] In some embodiments, the slurry distributor 220 can comprise any
suitable
substantially rigid material which can include a suitable material which can
allow the
size and shape of the outlet 130 to be modified using a profile system, for
example. For
example, a suitably rigid plastic, such as UHMW plastic, or metal can be used.
[00185] Referring to FIG. 4, the slurry distributor 220 has a two-piece
construction.
An upper piece 221 of the slurry distributor 220 includes a recess 227 adapted
to
receive a profiling system 132 therein. The two pieces 221, 223 can be
pivotally
movable with respect to each other about a hinge 205 at the rear end thereof
to allow
for ready access to an interior 207 of the slurry distributor 220. Mounting
holes 229 are
provided to facilitate the connection of the upper piece 221 and its mating
lower piece
223.
[00186] Referring to FIGS. 6-8, another embodiment of a slurry distributor 320
constructed in accordance with principles of the present disclosure is shown
which is
constructed from a rigid material. The slurry distributor 320 of FIGS. 6-8 is
similar to the
slurry distributor 220 of FIGS. 4 and 5 except that the first and second feed
inlets 324,
325 and the first and second entry segments 336, 337 of the slurry distributor
320 of
FIGS. 6-8 are disposed at a feed angle 0 with respect to the longitudinal axis
or
machine direction 50 of about 60 (see FIG. 7).
[00187] The slurry distributor 320 has a two-piece construction including an
upper
piece 321 and its mating lower piece 323. The two pieces 321, 323 of the
slurry
distributor 320 can be secured together using any suitable technique, such as
by using
fasteners through a corresponding number of mounting holes 329 provided in
each
piece 321, 323, for example. The upper piece 321 of the slurry distributor 320
includes
a recess 327 adapted to receive a profiling system 132 therein. The slurry
distributor
320 of FIGS. 6-8 is similar in other respects to the slurry distributor 220 of
FIGS. 4 and
5.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
36
[00188] Referring to FIGS. 9 and 10, the lower piece 323 of the slurry
distributor 320
of FIG. 6 is shown. The lower piece 323 defines a first portion 331 of the
interior
geometry 307 of the slurry distributor 320 of FIG. 6. The upper piece 323
defines a
symmetrical second portion of the interior geometry 307 such that when the
upper and
lower pieces 321, 323 are mated together, as shown in FIG. 6, they define the
complete
interior geometry 307 of the slurry distributor 320 of FIG. 6.
[00189] Referring to FIG. 9, the first and second shaped ducts 341, 343 are
adapted
to receive the first and second flows of slurry moving in the first and second
feed flow
directions 390, 391 and redirect the slurry flow direction by a change in
direction angle a
such that the first and second flows of slurry are conveyed into the
distribution conduit
328 moving substantially in the outlet flow direction 392, which is aligned
with the
machine direction or longitudinal axis 50.
[00190] FIGS. 11 and 12 depict another embodiment of a slurry distributor
support
300 for use with the slurry distributor 320 of FIG. 6. The slurry distributor
support 300
can include a top and bottom support plate 301, 302 constructed from a
suitably rigid
material, such as metal, for example. The support plates 301, 302 can be
secured to
the distributor through any suitable means. In use, the support plates 301,
302 can help
support the slurry distributor 320 in place over a machine line including a
conveyor
assembly supporting and transporting a moving cover sheet. The support plates
301,
302 can be mounted to appropriate uprights placed on either side of the
conveyor
assembly.
[00191] FIGS. 13 and 14 depict yet another embodiment of a slurry distributor
support
310 for use with the slurry distributor 320 of FIG. 6, which also includes top
and bottom
support plates 311, 312. Cutouts 313, 314, 318 in the top support plate 311
can make
the support 310 lighter than it would otherwise be and provide access to
portions of the
slurry distributor 320, such as those portions accommodating mounting
fasteners, for
example. The slurry distributor support 310 of FIGS. 13 and 14 can be similar
in other
respects to the slurry distributor support 300 of FIGS. 11 and 12.
[00192] FIGS. 15-19 illustrate another embodiment of a slurry distributor
420, which is
similar to the slurry distributor 320 of FIGS. 6-8, except that it is
constructed from a
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
37
substantially flexible material. The slurry distributor 420 of FIGS. 15-19
also includes
first and second feed inlets 324, 325 and first and second entry segments 336,
337
which are disposed at a feed angle 0 with respect to the longitudinal axis or
machine
direction 50 of about 60 (see FIG. 7). The interior geometry 307 of the
slurry distributor
420 of FIGS. 15-19 is similar to that of the slurry distributor 320 of FIGS. 6-
8, and like
reference numerals are used to indicate like structure.
[00193] FIGS. 17-19 progressively depict the interior geometry of the second
entry
segment 337 and the second shaped duct 343 of the slurry distributor 420 of
FIGS. 15
and 16. The cross-sectional areas 411, 412, 413, 414 of the outer and inner
guide
channels 367, 368 can become progressively smaller moving in a second flow
direction
397 toward the distribution outlet 330. The outer guide channel 367 can extend
substantially along the outer wall 357 of the second shaped duct 343 and along
the
sidewall 353 of the distribution conduit 328 to the distribution outlet 330.
The inner
guide channel 368 is adjacent the inner wall 358 of the second shaped duct 343
and
terminates at the peak 375 of the bisected connector segment 339. The slurry
distributor 420 of FIGS. 15-19 is similar in other respects to the slurry
distributor 120 of
FIG. 1 and the slurry distributor 320 of FIG. 6.
[00194] Referring to FIGS. 20 and 21, the illustrated embodiment of the slurry
distributor 420 is made from a flexible material, such as PVC or urethane, for
example.
A slurry distributor support 400 can be provided to help support the slurry
distributor
420. The slurry distributor support 400 can include a support member, which in
the
illustrated embodiment is in the form of a bottom support tray 401 filled with
a suitable
supporting medium 402 which defines a supporting surface 404. The supporting
surface 404 is configured to substantially conform to at least a portion of an
exterior of
at least one of the feed conduit 322 and the distribution conduit 328 to help
limit the
amount of relative movement between the slurry distributor 420 and the support
tray
401. In some embodiments, the supporting surface 404 can also help maintain
the
interior geometry of the slurry distributor 420 through which a slurry will
flow.
[00195] The slurry distributor support 400 can also include a movable support
assembly 405 disposed in spaced relationship to bottom support tray 401. The
movable
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
38
support assembly 405 can be positioned above the slurry distributor 420 and
adapted to
be placed in supporting relationship with the slurry distributor 420 to help
maintain the
interior geometry 307 of the slurry distributor in a desired configuration.
[00196] The movable support assembly 405 can include a support frame 407 and a
plurality of support segments 415, 416, 417, 418,419 which are movably
supported by
the support frame 407. The support frame 407 can be mounted to at least one of
the
bottom support tray 401 or a suitably arranged upright or uprights to retain
the support
frame 407 in fixed relationship to the bottom support tray 401.
[00197] In embodiments, at least one support segment 415, 416, 417, 418, 419
is
independently movable relative to another support segment 415, 416, 417, 418,
419. In
the illustrated embodiment, each support segment 415, 416, 417, 418,419 can be
independently movable relative to the support frame 407 over a predetermined
range of
travel. In embodiments, each support segment 415, 416, 417, 418, 419 is
movable over
a range of travel such that each support segment is in a range of positions
over which
the respective support segment 415, 416, 417, 418, 419 is in increasing
compressive
engagement with a portion of at least one of the feed conduit 322 and the
distribution
conduit 328.
[00198] The position of each support segment 415, 416, 417, 418, 419 can be
adjusted to place the support segments 415, 416, 417, 418, 419 in compressive
engagement with at least a portion of the slurry distributor 420. Each support
segment
415, 416, 417, 418, 419 can be independently adjusted to place each support
segment
415, 416, 417, 418, 419 either in further compressive engagement with at least
a
portion of the slurry distributor 420, thereby locally compressing the
interior of the slurry
distributor 420, or in reduced compressive engagement with at least a portion
of the
slurry distributor 420, thereby allowing the interior of the slurry
distributor 420 to expand
outwardly, such as in response to aqueous gypsum slurry flowing therethrough.
[00199] In the illustrated embodiment, each of the support segments 415, 416,
417 is
movable over a range of travel along the vertical axis 55. In other
embodiments, at
least one of the support segments can be movable along a different line of
action.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
39
[00200] The movable support assembly 405 includes a clamping mechanism 408
associated with each support segment 415, 416, 417, 418, 419. Each clamping
mechanism 408 can be adapted to selectively retain the associated support
segment
415, 416, 417, 418, 419 in a selected position relative to the support frame
407.
[00201] In the illustrated embodiment, a rod 409 is mounted to each support
segment
415, 416, 417, 418, 419 and extends upwardly through a corresponding opening
in the
support frame 407. Each clamping mechanism 408 is mounted to the support frame
407 and is associated with one of the rods 409 projecting from a respective
support
segment 415, 416, 417, 418, 419. Each clamping mechanism 408 can be adapted to
selectively retain the associated rod 409 in fixed relationship to the support
frame 407.
The illustrated clamping mechanisms 408 are conventional lever-actuated clamps
which
encircle the respective rod 409 and allow for infinitely variable adjustment
between the
clamping mechanism 408 and the associated rod 409.
[00202] As one skilled in the art will appreciate, any suitable clamping
mechanism 408
can be used in other embodiments. In some embodiments, each associated rod 409
can be moved via a suitable actuator (either hydraulic or electric, e.g.)
which is
controlled via a controller. The actuator can function as a clamping mechanism
by
retaining the associated support segment 415, 416, 417, 418, 419 in a fixed
position
relative to the support frame 407.
[00203] Referring to FIG. 21, the support segments 415, 416, 417, 418, 419 can
each
include a contacting surface 501, 502, 503, 504, 505 which is configured to
substantially
conform to a surface portion of the desired geometric shape of at least one of
the feed
conduit 322 and the distribution conduit 328 of the slurry distributor 420. In
the
illustrated embodiment, a distributor conduit support segment 415 is provided
which
includes a contacting surface 501 which conforms to the exterior and interior
shape of a
portion of the distributor conduit 328 over which the distributor conduit
support segment
415 is disposed. A pair of shaped duct support segments 416, 417 is provided
which
respectively include a contacting surface 502, 503 which conforms to the
exterior and
interior shape of a portion of the first and the second shaped ducts 341, 343,
respectively, over which the shaped duct support segments 416, 417 are
disposed. A
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
pair of entry support segments 418, 419 is provided which respectively include
a
contacting surface 504, 505 which conforms to the exterior and interior shape
of a
portion of the first and the second entry segments 336, 337, respectively,
over which the
shaped duct support segments 418, 419 are disposed. The contacting surfaces
501,
502, 503, 504, 505 are adapted to be placed in contacting relationship with a
selected
portion of the slurry distributor 420 to help maintain the contacted portion
of the slurry
distributor 420 in position to help define the interior geometry 307 of the
slurry distributor
420.
[00204] In use, the movable support assembly 405 can be operated to place each
support segment 415, 416, 417, 418, 419 independently in a desired
relationship with
the slurry distributor 420. The support segments 415, 416, 417, 418, 419 can
help
maintain the interior geometry 307 of the slurry distributor 420 to promote
the flow of
slurry therethrough and to help ensure the volume defined by the interior
geometry 307
is substantially filled with slurry during use. The location of the particular
contacting
surface of a given support segment 415, 416, 417, 418, 419 can be adjusted to
modify
locally the interior geometry of the slurry distributor 420. For example, the
distributor
conduit support segment 415 can be moved along the vertical axis 55 closer to
the
bottom support tray 401 to decrease the height of the distribution conduit 328
in an area
over which the distributor conduit support segment 415 is.
[00205] In other embodiments, the number of support segments can be varied. In
still
other embodiments, the size and/or shape of a given support segment can be
varied.
1002061 FIGS. 22-27 illustrate another embodiment of a slurry distributor 1420
constructed according to principles of the present disclosure. The slurry
distributor
1420 is made from a substantially flexible material, such as PVC or urethane,
for
example. The slurry distributor 1420 of FIGS. 22-27 also includes first and
second feed
inlets 1424, 1425 and first and second entry segments 1436, 1437 which are
disposed
at a feed angle e which is substantially parallel to the longitudinal axis or
machine
direction 50 (see FIG. 24).
[002071 The slurry distributor 1420 includes a bifurcated feed conduit 1422, a
distribution conduit 1428, a slurry wiping mechanism 1417, and a profiling
mechanism
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
41
1432. A slurry distributor support 1400 can be provided to help support the
slurry
distributor 1420.
[00208] Referring to FIGS. 22 and 23, the slurry distributor support 1400 can
include a
support member, which in the illustrated embodiment is in the form of a bottom
support
member 1401 which defines a supporting surface 1402. The supporting surface
1402
can be configured to substantially conform to at least a portion of an
exterior of at least
one of the feed conduit 1422 and the distribution conduit 1428 to help limit
the amount
of relative movement between the slurry distributor 1420 and the bottom
support
member 1401. In some embodiments, the supporting surface 1402 can also help
maintain the interior geometry of the slurry distributor 1420 through which a
slurry will
flow. In embodiments, additional anchoring structure can be provided to help
secure
the slurry distributor 1420 to the bottom support member 1401.
[00209] The slurry distributor support 1400 can also include an upper support
member
1404 disposed in spaced relationship to the bottom support member 1401. The
upper
support member 1404 can be positioned above the slurry distributor 1420 and
adapted
to be placed in supporting relationship with the slurry distributor 1420 to
help maintain
the interior geometry 1407 of the slurry distributor 1420 in a desired
configuration.
[00210] The upper support member 1404 can include a support frame 1407 and a
plurality of support segments 1413, 1415, 1416 which are fixedly supported by
the
support frame 1407. The support frame 1407 can be mounted to at least one of
the
bottom support member 1401 or one or more suitably arranged uprights to retain
the
support frame 1407 in fixed relationship to the bottom support tray 1401. The
support
segments 1413, 1415, 1416 can each have contacting surface which is configured
to
substantially conform to a surface portion of the desired geometric shape of
at least one
of the feed conduit 1422 and the distribution conduit 1428 of the slurry
distributor 1420.
In embodiments, the support frame 1407 can be adapted to movably adjust the
spatial
relationship between the support segments 1413, 1415, 1416 and the slurry
distributor
1420. For example in some embodiments, the support frame 1407 can move the
support segments 1413, 1415, 1416 over a range of travel over the vertical
axis 55.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
42
[00211] Referring to FIG. 22, the slurry wiping mechanism 1417 includes a pair
of
actuators 1510, 1511 operably arranged with a wiper blade 1514 to selectively
reciprocally move the wiper blade 1514. The actuators 1510, 1511 are mounted
to the
bottom support member 1401 adjacent a distal end 1515 of the distribution
conduit
1428. The wiper blade 1514 extends transversely between the actuators 1510,
1511.
[00212] Referring to FIG. 26, the distribution outlet 1430 includes an
outlet opening
1481 having a width W2, along the transverse axis 60. The wiper blade 1514
extends a
predetermined width W3 distance along the transverse axis 60. The width W2 of
the
outlet opening 1481 is smaller than the width W3 of the wiper blade 1514 such
that the
wiper blade 1514 is wider than the outlet opening 1481.
[00213] Referring to FIG. 28, in the illustrated embodiments, each actuator
1510,
1511 comprises a double-acting pneumatic cylinder having a reciprocally
movable
piston 1520. A rod 1522 of the piston 1520 is connected to the wiper blade
1514. In
embodiments, a pair of pneumatic air lines can be respectively connected to a
drive port
1525 and a retract port 1526. A source of pressurized gas 1530 can be
controlled using
a suitable control valve assembly 1532 controlled by a controller 1534 to
selectively
reciprocally move the wiper blade 1514 along the longitudinal axis 50. In
embodiments
an air line can tie the drive ports 1525 of both actuators 1510, 1511 together
in parallel,
and a separate air line can tie the retract ports 1526 of both actuators 1510,
1511
together in parallel. In other embodiments, the actuators can be anything
capable of
reciprocally moving the wiper blade including, for example, hand operated
devices.
[00214] The movable wiper blade 1514 is in contacting relationship with a
bottom
surface 1540 of the distribution conduit 1428. The wiper blade 1514 is
reciprocally
movable over a clearing path between a first position and a second position
(shown in
phantom lines). The clearing path is disposed adjacent the distal end 1515 of
the
distribution conduit 1428 which includes the distribution outlet 1430. The
wiper blade
reciprocally moves longitudinally along the clearing path. In the illustrated
embodiment,
the first position of the wiper blade 1514 is longitudinally upstream of the
distribution
outlet 1430, and the second position is longitudinally downstream of the
distribution
outlet 1430.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
43
1002151 The controller 1534 is adapted to selectively control the actuators to
reciprocally move the wiper blade 1514. In embodiments, the controller 1534 is
adapted to move the wiper blade 1514 in a clearing direction 1550 from the
first position
to the second position over a wiping stroke and to move the wiper blade in an
opposing,
return direction 1560 from the second position to the first position over a
return stroke.
In embodiments, the controller 1534 is adapted to move the wiper blade 1514
such that
the time to move over the wiping stroke is substantially the same as the time
to move
over the return stroke.
[002161 In embodiments, the controller 1534 can be adapted to move the wiper
blade
1514 reciprocally between the first position and the second position in a
cycle having a
sweep period. The sweep period includes a wiping portion comprising the time
to move
over the wiping stroke, a returning portion comprising the time to move over
the return
stroke, and an accumulation delay portion comprising a predetermined period of
time in
which the wiper blade 1514 remains in the first position. In embodiments, the
wiping
portion is substantially the same as the returning portion. In embodiments,
the
controller 1534 is adapted to adjustably vary the accumulation delay portion.
[002171 Referring to FIG. 34, the bottom support member 1401 supporting the
bottom
surface of the distribution conduit 1428 includes a perimeter 1565. The
distribution
outlet 1430 is longitudinally offset from the bottom support member 1401 such
that the
distal outlet portion 1515 of the distribution conduit 1428 extends from the
perimeter
1565 of the bottom support member 1401. Referring back to FIG. 28, the wiper
blade
1514 supports the distal outlet portion 1515 of the slurry distributor 1420
when the wiper
blade is in the first position.
[002181 Referring to FIG. 22, the profiling mechanism 1432 includes a
profiling
member 1610 in contacting relationship with the distribution conduit 1428 and
a support
assembly 1620 adapted to allow the profiling member 1610 to have at least two
degrees
of freedom. In embodiments, the profiling member is translatable along at
least one
axis and rotatable about at least one pivot axis. In embodiments the profiling
member is
movable along the vertical axis 55 and rotatable about a pivot axis 1630 that
is
substantially parallel to the longitudinal axis 50.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
44
[00219] Referring to FIGS. 26, 30 and 30A, the profiling member 1610 is
movable
over a range of travel such that the profiling member 1610 is in a range of
positions over
which the profiling member 1610 is in increasing compressive engagement with a
portion of the distribution conduit 1428 adjacent the distribution outlet 1430
to vary the
shape and/or size of the outlet opening 1430.
[00220] Referring to FIG. 26, the outlet opening 1481 of the distribution
outlet 1430
has a width W2 along the transverse axis 60. The contacting profiling segment
of the
profiling member 1410 has a width W4 extending a predetermined distance along
the
transverse axis. In embodiments the width W2 of the outlet opening 1481 is
larger than
the width W4 of the profiling member 1410. In other embodiments the width W2
of the
outlet opening 1481 is less than or equal to the width W4 of the profiling
member 1410.
The profiling member 1410 is positioned such that a pair of lateral portions
1631, 1632
of the distribution outlet 1430 is in lateral offset relationship to the
profiling member
1410 such that the profiling member does not engage the lateral portions 1631,
1632.
In some embodiments, the lateral portions 1631, 1632 can have a combined width
of
about one-fourth of the width W2 the outlet opening 1481.
[00221] Referring to FIG. 23, the support assembly 1620 includes a pair of
stationary
uprights 1642, 1643, a transverse stationary support member 1645, and a
transverse
pivotal support member 1647 that is pivotally connected to the transverse
stationary
support member 1645 using any suitable pivotal connection. The stationary
uprights
1642, 1643 can be mounted to the bottom support member 1401. The transverse
stationary support member 1645 can extend transversely between the stationary
uprights 1642, 1643.
[00222] Referring to FIGS. 29, 30, 30B, and 31, the pivotal support member
1647 is
rotatable about the pivot axis 1630 over an arc length 1652 with respect to
the
stationary support member 1645. In embodiments, the arc length 1652 allows for
tilting
a pivot end 1653 of the pivotal support member 1647 both upward above the
transverse
axis 60 and downward below the transverse axis 60. The pivotal support member
1647
supports the profiling member 1610.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
[00223] In embodiments, the profiling member 1610 is translatable along the
vertical
axis 55 and rotatable about the pivot axis 1630 which is substantially
parallel to the
longitudinal axis 50. The profiling member 1610 is rotatable about the pivot
axis 1630
over the arc length 1652 such that the profiling member 1610 is in a range of
positions
over which the profiling member is in variable compressive engagement with the
portion
of the distribution conduit 1428 across the transverse axis 60 such that the
height H2 of
the outlet opening 1481 varies along the transverse axis 60.
[00224] Referring to FIGS. 29 and 33, the profiling member 1610 includes an
engagement segment 1660 extending generally longitudinally and transversely
and a
translation adjustment rod 1662 extending generally vertically from the
engagement
segment 1660. The translation adjustment rod 1662 of the profiling member 1610
is
movably secured to the pivotal support member 1647 of the support assembly
1620
such that the profiling member 1610 is movable along the vertical axis 55 over
a range
of vertical positions. A pair of translation guide rods 1663, 1665 are
connected to the
engagement segment 1660 and extends through a respective collar 1667, 1668
mounted to the pivotal support member 1647. The guide rods 1663, 1665 are
movable
with respect to the collars 1667, 1668 along the vertical axis 55.
[00225] The support assembly 1620 can include a clamp mechanism adapted to
selectively engage the translation adjustment rod 1662 to secure the profiling
member
1610 in a selected one of the range of vertical positions. In the illustrated
embodiment,
a threaded connection between the translation adjustment rod 1662 and the
pivotal
support member 1647 functions as a clamp mechanism. A lock nut 1664 is
provided to
secure the threaded translation adjustment rod 1662 in place. An elastic nut
1666 is
disposed near a distal end 1657 of the translation adjustment rod 1662 to
maintain a
sufficient clearance for a cap screw 1669 (see FIG. 30C) affixed to the distal
end to be
allowed to rotate. Referring to FIG. 30C, a blind hole 1658 is defined in the
profiling
member 1610 to accommodate the cap screw 1669 to allow the cap screw to rotate
about the axis of the translation adjustment rod 1662.
[00226] Referring to FIGS. 30B and 31, the support assembly 1620 can be
adapted to
rotatably support the profiling member 1610 such that the profiling member
1610 is
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
46
rotatable about the pivot axis 1630 over a range of positions along the arc
length 1652.
The support assembly 1620 includes a rotation adjustment rod 1670 extending
between
the stationary support member 1645 and the pivotal support member 1647 by way
of a
support bracket 1672 connected to the stationary support member 1645 (see FIG.
31
also). The rotation adjustment rod 1670 is movably secured to the stationary
support
member 1645 through a threaded connection with the support bracket 1672 such
that
moving the rotation adjustment rod 1670 with respect to the stationary support
member
1645, by rotating its T-handle, pivots the pivotal support member 1647 about
the pivot
axis 1630 with respect to the stationary support member 1645. The support
bracket
1672 can be configured such that it can allow for some flexing during a tilt
operation.
Shaft collars 1673, 1674 can be provided for added reliability.
[00227] The support assembly 1620 can include a clamp mechanism adapted to
selectively engage the rotation adjustment rod 1670 to secure the profiling
member
1610 in a selected one of the range of positions along the arc length 1652. In
the
illustrated embodiment, a jam nut 1677 can be provided to lock the threaded
rod 1670
to the barrel nut 1679.
[00228] Referring to FIGS. 34 and 40, the bifurcated feed conduit 1422 of the
slurry
distributor 1420 includes a first and a second feed portion 1701, 1702. Each
of the first
and second feed portions 1701, 1702 has a respective entry segment 1436, 1437
with a
feed inlet 1424, 1425 and a feed entry outlet 1710, 1711 in fluid
communication with the
feed inlet 1424, 1425, a shaped duct 1441, 1443 having a bulb portion 1720,
1721 (see
FIG. 41 also) in fluid communication with the feed entry outlet 1710, 1711 of
the
respective entry segment 1436, and a transition segment 1730, 1731 in fluid
communication with the respective bulb portion 1720, 1721.
[00229] Referring to FIG. 34, the first and second feed inlets 1424, 1425 and
the first
and second entry segments 1436, 1437 can be disposed at a respective feed
angle 9,
measured as the degree of rotation relative to the vertical axis 55, in a
range up to
about 135 with respect to the longitudinal axis 50. The illustrated first and
second feed
inlets 1424, 1425 and the first and second entry segments 1436, 1437 are
disposed at a
respective feed angle 9 substantially aligned with the longitudinal axis 50.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
47
[00230] The first feed portion 1701 is substantially identical the second feed
portion
1702. It should be understood, therefore, that the description of one feed
portion is
equally applicable to the other feed portion, as well. In other embodiments
there can be
only a single feed portion or in still further embodiments there can be more
than two
feed portions.
[00231] Referring to FIG. 35, the entry segment 1436 is generally cylindrical
and
extends along a first feed flow axis 1735. The first feed flow axis 1735 of
the illustrated
entry segment 1436 extends generally along the vertical axis 55.
[00232] In other embodiments, the first feed flow axis 1735 can have a
different
orientation with respect to the plane 57 defined by the longitudinal axis 50
and the
transverse axis 60. For example, in other embodiments, the first feed flow
axis 1735
can be disposed at a feed pitch angle a, measured as the degree of rotation
relative to
the transverse axis 60, that is non-perpendicular to the plane 57 defined by
the
longitudinal axis 50 and the transverse axis 60. In embodiments the pitch
angle a,
measured from the longitudinal axis 50 in a direction opposing the machine
direction 92
upward to the vertical axis 55 as shown in FIG. 35, can be anywhere in a range
from
about zero to about one hundred thirty-five degrees, from about fifteen to
about one
hundred twenty degrees in other embodiments, from about thirty to about one
hundred
five degrees in still other embodiments, from about forty-five to about one
hundred five
degrees in yet other embodiments, and from about seventy-five to about one
hundred
five degrees in other embodiments. In other embodiments, the first feed flow
axis 1735
can be disposed at a feed roll angle, measured as the degree of rotation
relative to the
longitudinal axis 50, that is non-perpendicular to the plane 57 defined by the
longitudinal
axis 50 and the transverse axis 60.
[00233] Referring to FIG. 34, the shaped duct 1441 includes a pair of lateral
sidewalls
1740, 1741 and the bulb portion 1720. The shaped duct 1441 is in fluid
communication
with the feed entry outlet 1711 of the entry segment 1436. Referring to FIG.
35, the
bulb portion 1720 is configured to reduce the average velocity of a flow of
slurry moving
from the entry segment 1436 through the bulb portion 1720 to the transition
segment
1730. In embodiments, the bulb portion 1720 is configured to reduce the
average
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
48
velocity of a flow of slurry moving from the entry segment 1436 through the
bulb portion
1720 to the transition segment 1730 by at least twenty percent.
100234] Referring to FIGS. 45-47, the bulb portion 1720 has an area of
expansion
1750 with a cross-sectional flow area that is greater than a cross-sectional
flow area of
an adjacent area upstream from the area of expansion relative to a flow
direction 1752
from the feed inlet 1424 toward the distribution outlet 1430 of the
distribution conduit
1428. In embodiments, the bulb portion 1720 has a region 1752 with a cross-
sectional
area in a plane perpendicular to the first flow axis 1735 that is larger than
the cross-
sectional area of the feed entry outlet 1711.
[00235] The shaped duct 1441 has a convex interior surface 1758 in confronting
relationship with the feed entry outlet 1711 of the entry segment 1436. The
bulb portion
1720 has a generally radial guide channel 1460 disposed adjacent the convex
interior
surface. The guide channel 1460 is configured to promote radial flow in a
plane
substantially perpendicular to the first feed flow axis 1735. Referring to
FIG. 45, the
convex interior surface 1758 is configured to define a central restriction
1762 in the flow
path which also helps increase the average velocity of the slurry in the
radial guide
channel 1760.
[00236] The shaped duct 1441 can be configured such that a flow of slurry
moving
through a region adjacent the convex interior surface 1758 and adjacent at
least one of
the lateral sidewalls 1740, 1741 toward the distribution outlet 1430 has a
swirl motion
(Sm) from about zero to about 10, up to about 3 in other embodiments, and from
about
0.5 to about 5 in still other embodiments. In embodiments, the flow of slurry
moving
through the region adjacent the convex interior surface 1758 and adjacent at
least one
of the lateral sidewalls 1740, 1741 toward the distribution outlet 1430 has a
swirl angle
(Sm) from about 0 to about 84 , and from about 10 to about 80 in other
embodiments.
[00237] Referring to FIGS. 34 and 35, the transition segment 1730 is in fluid
communication with the bulb portion 1720. The illustrated transition segment
1730
extends along the longitudinal axis 50. The transition segment 1730 is
configured such
that its width, measured along the transverse axis 60, increases in the
direction of flow
from the bulb portion 1720 to the discharge outlet 1430. The transition
segment 1730
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
49
extends along a second feed flow axis 1770, which is in non-parallel
relationship with
the first feed flow axis 1735.
[00238] In embodiments, the first feed flow axis 1735 is substantially
perpendicular to
the longitudinal axis 50. In embodiments, the first feed flow axis 1735 is
substantially
parallel to the vertical axis 55, which is perpendicular to the longitudinal
axis 50 and the
transverse axis 60. In embodiments, the second feed flow axis 1770 is disposed
at a
respective feed angle e in a range up to about 135 with respect to the
longitudinal axis
50.
[00239] In embodiments, the feed conduit 1422 includes a bifurcated connector
segment 1439 including first and second guide surfaces 1780, 1781. In
embodiments,
the first and second guide surfaces 1781 can be respectively adapted to
redirect first
and second flows of slurry entering the feed conduit through the first and
second inlets
1424, 1425 by a change in direction angle in a range up to about 135 to an
outlet flow
direction.
[00240] Referring to FIGS. 41-43, each of the shaped ducts 1441, 1443 has a
concave exterior surface 1790, 1791 substantially complementary to the shape
of the
convex interior surface 1758 thereof and in underlying relationship therewith.
Each
concave exterior surface 1790, 1791 defines a recess 1794, 1795.
[00241] Referring to FIGS. 27, 35, and 36, a support insert 1801, 1802 is
disposed
within each recess 1794, 1795 of the slurry distributor 1420. The support
inserts 1801,
1802 are disposed in underlying relationship to the respective convex interior
surfaces
of the shaped ducts 1441, 1443. The support inserts 1801, 1802 can be made
from any
suitable material which will help support the slurry distributor and maintain
a desired
shape for the overlying interior convex surface. In the illustrated
embodiment, the
support inserts 1801, 1802 are substantially the same. In other embodiments,
different
support inserts can be used or in still further embodiments the inserts are
not used.
[00242] Referring to FIGS. 37-39, the rigid support insert 1801 includes a
support
surface 1810 substantially conforming to the shape of the convex interior
surface of the
shaped duct. In embodiments, the shaped duct of the slurry distributor can be
made
from a sufficiently flexible material such that the convex interior surface is
defined by
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
support surface 1810 of the support insert 1801. In such cases, the concave
exterior
surface of the shaped duct can be omitted.
[00243] The support insert 1801 includes a feed end 1820 and a distribution
end
1822. The support insert 1801 extends along a central support axis 1825. The
support
insert 1801 is substantially symmetrical about the support axis 1825. The
support insert
1801 is asymmetrical about a central axis 1830 perpendicular to the support
axis 1825.
[00244] Referring to FIG. 34, the distribution conduit 1428 extends generally
along the
longitudinal axis 50 and includes an entry portion 1452 and a distribution
outlet 1430 in
fluid communication with the entry portion 1452. The entry portion 1452 is in
fluid
communication with the first and second feed inlets 1424, 1425 of the feed
conduit
1422. The width of the distribution conduit 1428 increases from the entry
portion 1452
to the distribution outlet 1430. In other embodiments, however, the width of
the
distribution conduit 1428 decreases or is constant from the entry portion 1452
to the
distribution outlet 1430.
[00245] The entry portion 1452 includes an entry opening 1453 having a
distribution
entry width W5, along the transverse axis 60, and an entry height H4, along
the vertical
axis 55, wherein the distribution entry width W5 is less than the width W2 of
the outlet
opening 1481 of the distribution outlet 1430. In other embodiments the
distribution entry
width W5 is greater than or equal to the width W2 of the outlet opening 1481
of the
distribution outlet 1430. In embodiments, the width-to-height ratio of the
outlet opening
1481 is about four or more.
[00246] In embodiments, at least one of the feed conduit 1422 and the
distribution
conduit 1428 includes a flow stabilization region adapted to reduce an average
feed
velocity of a flow of slurry entering the feed inlets 1424, 1425 and moving to
the
distribution outlet 1430 such that the flow of slurry discharges from the
distribution outlet
at an average discharge velocity that is at least twenty percent less than the
average
feed velocity.
[00247] FIGS. 44-53 progressively depict the interior geometry 1407 of a half
portion
1504 of the slurry distributor 1420 of FIG. 22. The slurry distributor 1420 of
FIG. 22 is
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
51
similar in other respects to the slurry distributor 120 of FIG. 1 and the
slurry distributor
420 of FIG. 20.
[00248] Any suitable technique for making a slurry distributor constructed in
accordance with principles of the present disclosure can be used. For example,
in
embodiments where the slurry distributor is made from a flexible material,
such as PVC
or urethane, a multi-piece mold can be used. In some embodiments, the mold
piece
areas are about 150% or less than the area of the molded slurry distributor
through
which the mold piece is being pulled during removal, about 125% or less in
other
embodiments, about 115% or less in still other embodiments, and about 110% or
less in
yet other embodiments.
[00249] Referring to FIGS. 54 and 55, an embodiment of a multi-piece mold 550
suitable for use in making the slurry distributor 120 of FIG. 1 from a
flexible material,
such as PVC or urethane is shown. The illustrated multi-piece mold 550
includes five
mold segments 551, 552, 553, 554, 555. The mold segments 551, 552, 553, 554,
555
of the multi-piece mold 550 can be made from any suitable material, such as
aluminum,
for example.
[00250] In the illustrated embodiment, the distributor conduit mold segment
551 is
configured to define the interior flow geometry of the distributor conduit
128. The first
and second shaped duct mold segments 552, 553 are configured to define the
interior
flow geometry of the first and the second shaped ducts 141, 143. The first and
second
entry mold segments 554, 555 define the interior flow geometry of the first
entry
segment 136 and the first feed inlet 124 and of the second entry segment 137
and the
second feed inlet 125, respectively. In other embodiments, the multi-piece
mold can
include a different number of mold segments and/or the mold segments can have
different shapes and/or sizes.
[00251] Referring to FIG. 54, connecting bolts 571, 572, 573 can be inserted
through
two or more mold segments to interlock and align the mold segments 551, 552,
553,
554, 555 such that a substantially continuous exterior surface 580 of the
multi-piece
mold 550 is defined. In some embodiments, a distal portion 575 of the
connecting bolts
571, 572, 573 includes an external thread that is configured to threadingly
engage one
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
52
of the mold segments 551, 552, 553, 554, 555 to interconnect at least two of
the mold
segments 551, 552, 553, 554, 555. The exterior surface 580 of the multi-piece
mold
550 is configured to define the interior geometry of the molded slurry
distributor 120 so
that flashing at the joints is reduced. The connecting bolts 571, 572, 573 can
be
removed to disassemble the multi-piece mold 550 during removal of the mold 550
from
the interior of the molded slurry distributor 120.
[00252] The assembled multi-piece mold 550 is dipped into a solution of
flexible
material, such as PVC or urethane, such that the mold 550 is completely
submersed in
the solution. The mold 550 can then be removed from the dipped material. An
amount
of the solution can adhere to the exterior surface 580 of the multi-piece mold
550 which
will constitute the molded slurry distributor 120 once the solution changes to
a solid
form. In embodiments, the multi-piece mold 550 can be used in any suitable
dipping
process to form the molded piece.
[00253] By making the mold 550 out of multiple separate aluminum pieces ¨ in
the
illustrated embodiment, five pieces ¨ that have been designed to fit together
to provide
the desired interior flow geometry, the mold segments 551, 552, 553, 554, 555
can be
disengaged from each other and pulled out from the solution once it has begun
to set
but while it is still warm. At sufficiently-high temperatures, the flexible
material is pliable
enough to pull larger calculated areas of the aluminum mold pieces 551, 552,
553, 554,
555 through the smaller calculated areas of the molded slurry distributor 120
without
tearing it. In some embodiments, the largest mold piece area is up to about
150% of
the smallest area of the molded slurry distributor cavity area through which
the
particular mold piece traverses transversely during the removal process, up to
about
125% in other embodiments, up to about 115% in still other embodiments, and up
to
about 110% in yet other embodiments.
[00254] Referring to FIG. 56, an embodiment of a multi-piece mold 650 suitable
for
use in making the slurry distributor 320 of FIG. 6 from a flexible material,
such as PVC
or urethane is shown. The illustrated multi-piece mold 650 includes five mold
segments
651, 652, 653, 654, 655. The mold segments 651, 652, 653, 654, 655 of the
multi-piece
mold 550 can be made from any suitable material, such as aluminum, for
example. The
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
53
mold segments 651, 652, 653, 654, 655 are shown in a disassembled condition in
FIG.
56.
[00255] Connecting bolts can be used to removably connect the mold segments
651,
652, 653, 654, 655 together to assemble the mold 650 such that a substantially
continuous exterior surface of the multi-piece mold 650 is defined. The
exterior surface
of the multi-piece mold 650 defines the internal flow geometry of the slurry
distributor
220 of FIG. 6. The mold 650 can be similar in construction to the mold 550 of
FIGS. 54
and 55 in that each piece of the mold 650 of FIG. 56 is constructed such that
its area is
within a predetermined amount of the smallest area of the molded slurry
distributor 220
through which the mold piece must traverse when it is being removed (e.g., up
to about
150% of the smallest area of the molded slurry distributor cavity area through
which the
particular mold piece traverses transversely during the removal process in
some
embodiments, up to about 125% in other embodiments, up to about 115% in still
other
embodiments, and up to about 110% in yet other embodiments).
[00256] Referring to FIGS. 57 and 58, an embodiment of a mold 750 for use in
making one of the pieces 221, 223 of the two-piece slurry distributor 220 of
FIG. 4 is
shown. Referring to FIG. 57, mounting bore-defining elements 752 can be
included to
define mounting bores in the piece of the two-piece slurry distributor 220 of
FIG. 4 being
made to facilitate its connection with the other piece.
[00257] Referring to FIGS. 57 and 58, the mold 750 includes a mold surface 754
projecting from a bottom surface 756 of the mold 750. A boundary wall 756
extends
along the vertical axis and defines the depth of the mold. The mold surface
754 is
disposed within the boundary wall 756. The boundary wall 756 is configured to
allow
the volume of a cavity 758 defined within the boundary wall to be filled with
molten mold
material such that the mold surface 754 is immersed. The mold surface 754 is
configured to be a negative image of the interior flow geometry defined by the
particular
piece of the two-piece distributor being molded.
[00258] In use, the cavity 758 of the mold 750 can be filled with a molten
material
such that the mold surface is immersed and the cavity 758 is filled with
molten material.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
54
The molten material can be allowed to cool and removed from the mold 750.
Another
mold can be used to form the mating piece of the slurry distributor 220 of
FIG. 4.
[00259] Referring to FIG. 59, an embodiment of a gypsum slurry mixing and
dispensing assembly 810 includes a gypsum slurry mixer 912 in fluid
communication
with a slurry distributor 820 similar to the slurry distributor 320 shown in
FIG. 6. The
gypsum slurry mixer 812 is adapted to agitate water and calcined gypsum to
form an
aqueous calcined gypsum slurry. Both the water and the calcined gypsum can be
supplied to the mixer 812 via one or more inlets as is known in the art. Any
suitable
mixer (e.g., a pin mixer) can be used with the slurry distributor.
1002601 The slurry distributor 820 is in fluid communication with the gypsum
slurry
mixer 812. The slurry distributor 820 includes a first feed inlet 824 adapted
to receive a
first flow of aqueous calcined gypsum slurry from the gypsum slurry mixer 812
moving
in a first feed direction 890, a second feed inlet 825 adapted to receive a
second flow of
aqueous calcined gypsum slurry from the gypsum slurry mixer 812 moving in a
second
feed direction 891, and a distribution outlet 830 in fluid communication with
both the first
and the second feed inlets 824, 825 and adapted such that the first and second
flows of
aqueous calcined gypsum slurry discharge from the slurry distributor 820
through the
distribution outlet 830 substantially along a machine direction 50.
1002611 The slurry distributor 820 includes a feed conduit 822 in fluid
communication
with a distribution conduit 828. The feed conduit includes the first feed
inlet 824 and the
second feed inlet 825 disposed in spaced relationship to the first feed inlet
824, which
are both disposed at a feed angle 9 of about 60 with respect to the machine
direction
50. The feed conduit 822 includes structure therein adapted to receive the
first and
second flows of slurry moving in the first and second feed flow direction 890,
891 and
redirect the slurry flow direction by a change in direction angle a (see FIG.
9) such that
the first and second flows of slurry are conveyed into the distribution
conduit 828
moving substantially in the outlet flow direction 892, which is substantially
aligned with
the machine direction 50. The first and second feed inlets 824, 825 each has
an
opening with a cross-sectional area, and the entry portion 852 of the
distribution conduit
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
828 has an opening with a cross-sectional area which is greater than the sum
of the
cross-sectional areas of the openings of the first and second feed inlets 824,
825.
[00262] The distribution conduit 828 extends generally along the longitudinal
axis or
machine direction 50, which is substantially perpendicular to a transverse
axis 60. The
distribution conduit 828 includes an entry portion 852 and the distribution
outlet 830.
The entry portion 852 is in fluid communication with the first and second feed
inlets 824,
825 of the feed conduit 822 such that the entry portion 852 is adapted to
receive both
the first and the second flows of aqueous calcined gypsum slurry therefrom.
The
distribution outlet 830 is in fluid communication with the entry portion 852.
The
distribution outlet 830 of the distribution conduit 828 extends a
predetermined distance
along the transverse axis 60 to facilitate the discharge of the combined first
and second
flows of aqueous calcined gypsum slurry in the cross-machine direction or
along the
transverse axis 60. The slurry distributor 820 can be similar in other
respects to the
slurry distributor 320 of FIG. 6.
[00263] A delivery conduit 814 is disposed between and in fluid communication
with
the gypsum slurry mixer 812 and the slurry distributor 820. The delivery
conduit 814
includes a main delivery trunk 815, a first delivery branch 817 in fluid
communication
with the first feed inlet 824 of the slurry distributor 820, and a second
delivery branch
818 in fluid communication with the second feed inlet 825 of the slurry
distributor 820.
The main delivery trunk 815 is in fluid communication with both the first and
second
delivery branches 817, 818. In other embodiments, the first and second
delivery
branches 817, 818 can be in independent fluid communication with the gypsum
slurry
mixer 812.
[00264] The delivery conduit 814 can be made from any suitable material and
can
have different shapes. In some embodiments, the delivery conduit 814 can
comprise a
flexible conduit.
[00265] An aqueous foam supply conduit 821 can be in fluid communication with
at
least one of the gypsum slurry mixer 812 and the delivery conduit 814. An
aqueous
foam from a source can be added to the constituent materials through the foam
supply
conduit 821 at any suitable location downstream of the mixer 812 and/or in the
mixer
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
56
812 itself to form a foamed gypsum slurry that is provided to the slurry
distributor 220.
In the illustrated embodiment, the foam supply conduit 821 is disposed
downstream of
the gypsum slurry mixer 812. In the illustrated embodiment, the aqueous foam
supply
conduit 821 has a manifold-type arrangement for supplying foam to an injection
ring or
block associated with the delivery conduit 814 as described in U.S. Patent No.
6,874,930, for example.
[00266] In other embodiments, one or more foam supply conduits can be provided
that are in fluid communication with the mixer 812. In yet other embodiments,
the
aqueous foam supply conduit(s) can be in fluid communication with the gypsum
slurry
mixer alone. As will be appreciated by those skilled in the art, the means for
introducing
aqueous foam into the gypsum slurry in the gypsum slurry mixing and dispensing
assembly 810, including its relative location in the assembly, can be varied
and/or
optimized to provide a uniform dispersion of aqueous foam in the gypsum slurry
to
produce board that is fit for its intended purpose.
[00267] Any suitable foaming agent can be used. Preferably, the aqueous foam
is
produced in a continuous manner in which a stream of the mix of foaming agent
and
water is directed to a foam generator, and a stream of the resultant aqueous
foam
leaves the generator and is directed to and mixed with the calcined gypsum
slurry.
Some examples of suitable foaming agents are described in U.S. Patent Nos.
5,683,635
and 5,643,510, for example.
[00268] When the foamed gypsum slurry sets and is dried, the foam dispersed in
the
slurry produces air voids therein which act to lower the overall density of
the wallboard.
The amount of foam and/or amount of air in the foam can be varied to adjust
the dry
board density such that the resulting wallboard product is within a desired
weight range.
[00269] One or more flow-modifying elements 823 can be associated with the
delivery
conduit 814 and adapted to control the first and the second flows of aqueous
calcined
gypsum slurry from the gypsum slurry mixer 812. The flow-modifying element(s)
823
can be used to control an operating characteristic of the first and second
flows of
aqueous calcined gypsum slurry. In the illustrated embodiment of FIG. 59, the
flow-
modifying element(s) 823 is associated with the main delivery trunk 815.
Examples of
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
57
suitable flow-modifying elements include volume restrictors, pressure
reducers,
constrictor valves, canisters, etc., including those described in U.S. Pat.
Nos. 6,494,609;
6,874,930; 7,007,914; and 7,296,919, for example.
[00270] The main delivery trunk 815 can be joined to the first and second
delivery
branches 817, 818 via a suitable Y-shaped flow splitter 819. The flow splitter
819 is
disposed between the main delivery trunk 815 and the first delivery branch 817
and
between the main delivery trunk 815 and the second delivery branch 818. In
some
embodiments, the flow splitter 819 can be adapted to help split the first and
second
flows of gypsum slurry such that they are substantially equal. In other
embodiments,
additional components can be added to help regulate the first and second flows
of
slurry.
[00271] In use, an aqueous calcined gypsum slurry is discharged from the mixer
812.
The aqueous calcined gypsum slurry from the mixer 812 is split in the flow
splitter 819
into the first flow of aqueous calcined gypsum slurry and the second flow of
aqueous
calcined gypsum slurry. The aqueous calcined gypsum slurry from the mixer 812
can
be split such that the first and second flows of aqueous calcined gypsum
slurry are
substantially balanced.
[00272] Referring to FIG. 60, another embodiment of a gypsum slurry mixing and
dispensing assembly 910 is shown. The gypsum slurry mixing and dispensing
assembly 910 includes a gypsum slurry mixer 912 in fluid communication with a
slurry
distributor 920. The gypsum slurry mixer 912 is adapted to agitate water and
calcined
gypsum to form an aqueous calcined gypsum slurry. The slurry distributor 920
can be
similar in construction and function to the slurry distributor 320 of FIG. 6.
[00273] A delivery conduit 914 is disposed between and in fluid communication
with
the gypsum slurry mixer 912 and the slurry distributor 920. The delivery
conduit 914
includes a main delivery trunk 915, a first delivery branch 917 in fluid
communication
with the first feed inlet 924 of the slurry distributor 920, and a second
delivery branch
918 in fluid communication with the second feed inlet 925 of the slurry
distributor 920.
[00274] The main delivery trunk 915 is disposed between and in fluid
communication
with the gypsum slurry mixer 912 and both the first and the second delivery
branches
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
58
917, 918. An aqueous foam supply conduit 921 can be in fluid communication
with at
least one of the gypsum slurry mixer 912 and the delivery conduit 914. In the
illustrated
embodiment, the aqueous foam supply conduit 921 is associated with the main
delivery
trunk 915 of the delivery conduit 914.
[00275] The first delivery branch 917 is disposed between and in fluid
communication
with the gypsum slurry mixer 912 and the first feed inlet 924 of the slurry
distributor 920.
At least one first flow-modifying element 923 is associated with the first
delivery branch
917 and is adapted to control the first flow of aqueous calcined gypsum slurry
from the
gypsum slurry mixer 912.
[00276] The second delivery branch 918 is disposed between and in fluid
communication with the gypsum slurry mixer 912 and the second feed inlet 925
of the
slurry distributor 920. At least one second flow-modifying element 927 is
associated
with the second delivery branch 918 and is adapted to control the second flow
of
aqueous calcined gypsum slurry from the gypsum slurry mixer 912.
[00277] The first and second flow-modifying elements 923, 927 can be operated
to
control an operating characteristic of the first and second flows of aqueous
calcined
gypsum slurry. The first and second flow-modifying elements 923, 927 can be
independently operable. In some embodiments, the first and second flow-
modifying
elements 923, 927 can be actuated to deliver first and second flows of
slurries that
alternate between a relatively slower and relatively faster average velocity
in opposing
fashion such that at a given time the first slurry has an average velocity
that is faster
than that of the second flow of slurry and at another point in time the first
slurry has an
average velocity that is slower than that of the second flow of slurry.
[00278] As one of ordinary skill in the art will appreciate, one or both of
the webs of
cover sheet material can be pre-treated with a very thin relatively denser
layer of
gypsum slurry (relative to the gypsum slurry comprising the core), often
referred to as a
skim coat in the art, and/or hard edges, if desired. To that end, the mixer
912 includes a
first auxiliary conduit 929 that is adapted to deposit a stream of dense
aqueous calcined
gypsum slurry that is relatively denser than the first and second flows of
aqueous
calcined gypsum slurry delivered to the slurry distributor (i.e., a "face skim
coat/hard
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
59
edge stream"). The first auxiliary conduit 929 can deposit the face skim
coat/hard edge
stream upon a moving web of cover sheet material upstream of a skim coat
roller 931
that is adapted to apply a skim coat layer to the moving web of cover sheet
material and
to define hard edges at the periphery of the moving web by virtue of the width
of the
roller 931 being less than the width of the moving web as is known in the art.
Hard
edges can be formed from the same dense slurry that forms the thin dense layer
by
directing portions of the dense slurry around the ends of the roller used to
apply the
dense layer to the web.
[00279] The mixer 912 can also include a second auxiliary conduit 933 adapted
to
deposit a stream of dense aqueous calcined gypsum slurry that is relatively
denser than
the first and second flows of aqueous calcined gypsum slurry delivered to the
slurry
distributor (i.e., a "back skim coat stream"). The second auxiliary conduit
933 can
deposit the back skim coat stream upon a second moving web of cover sheet
material
upstream (in the direction of movement of the second web) of a skim coat
roller 937 that
is adapted to apply a skim coat layer to the second moving web of cover sheet
material
as is known in the art (see FIG. 61 also).
[00280] In other embodiments, separate auxiliary conduits can be connected to
the
mixer to deliver one or more separate edge streams to the moving web of cover
sheet
material. Other suitable equipment (such as auxiliary mixers) can be provided
in the
auxiliary conduits to help make the slurry therein denser, such as by
mechanically
breaking up foam in the slurry and/or by chemically breaking down the foam
through
use of a suitable de-foaming agent.
[00281] In yet other embodiments, first and second delivery branches can each
include a foam supply conduit therein which are respectively adapted to
independently
introduce aqueous foam into the first and second flows of aqueous calcined
gypsum
slurry delivered to the slurry distributor. In still other embodiments, a
plurality of mixers
can be provided to provide independent streams of slurry to the first and
second feed
inlets of a slurry distributor constructed in accordance with principles of
the present
disclosure. It will be appreciated that other embodiments are possible.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
[00282] The gypsum slurry mixing and dispensing assembly 910 of FIG. 60 can be
similar in other respects to the gypsum slurry mixing and dispensing assembly
810 of
FIG. 59. It is further contemplated that other slurry distributors constructed
in
accordance with principles of the present disclosure can be used in other
embodiments
of a cementitious slurry mixing and dispensing assembly as described herein.
[00283] Referring to FIG. 61, an exemplary embodiment of a wet end 1011 of a
gypsum wallboard manufacturing line is shown. The wet end 1011 includes a
gypsum
slurry mixing and dispensing assembly 1010 having a gypsum slurry mixer 1012
in fluid
communication with a slurry distributor 1020 similar in construction and
function to the
slurry distributor 320 of FIG. 6, a hard edge/face skim coat roller 1031
disposed
upstream of the slurry distributor 1020 and supported over a forming table
1038 such
that a first moving web 1039 of cover sheet material is disposed therebetween,
a back
skim coat roller 1037 disposed over a support element 1041 such that a second
moving
web 1043 of cover sheet material is disposed therebetween, and a forming
station 1045
adapted to shape the preform into a desired thickness. The skim coat rollers
1031,
1037, the forming table 1038, the support element 1041, and the forming
station 1045
can all comprise conventional equipment suitable for their intended purposes
as is
known in the art. The wet end 1011 can be equipped with other conventional
equipment as is known in the art.
[00284] In another aspect of the present disclosure, a slurry distributor
constructed in
accordance with principles of the present disclosure can be used in a variety
of
manufacturing processes. For example, in one embodiment, a slurry distribution
system can be used in a method of preparing a gypsum product. A slurry
distributor
can be used to distribute an aqueous calcined gypsum slurry upon the first
advancing
web 1039.
[00285] Water and calcined gypsum can be mixed in the mixer 1012 to form the
first
and second flows 1047, 1048 of aqueous calcined gypsum slurry. In some
embodiments, the water and calcined gypsum can be continuously added to the
mixer
in a water-to-calcined gypsum ratio from about 0.5 to about 1.3, and in other
embodiments of about 0.75 or less.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
61
[00286] Gypsum board products are typically formed "face down" such that the
advancing web 1039 serves as the "face" cover sheet of the finished board. A
face
skim coat/hard edge stream 1049 (a layer of denser aqueous calcined gypsum
slurry
relative to at least one of the first and second flows of aqueous calcined
gypsum slurry)
can be applied to the first moving web 1039 upstream of the hard edge/face
skim coat
roller 1031, relative to the machine direction 1092, to apply a skim coat
layer to the first
web 1039 and to define hard edges of the board.
[00287] The first flow 1047 and the second flow 1048 of aqueous calcined
gypsum
slurry are respectively passed through the first feed inlet 1024 and the
second feed inlet
1025 of the slurry distributor 1020. The first and second flows 1047, 1048 of
aqueous
calcined gypsum slurry are combined in the slurry distributor 1020. The first
and
second flows 1047, 1048 of aqueous calcined gypsum slurry move along a flow
path
through the slurry distributor 1020 in the manner of a streamline flow,
undergoing
minimal or substantially no air-liquid slurry phase separation and
substantially without
undergoing a vortex flow path.
[00288] The first moving web 1039 moves along the longitudinal axis 50. The
first
flow 1047 of aqueous calcined gypsum slurry passes through the first feed
inlet 1024,
and the second flow 1048 of aqueous calcined gypsum slurry passes through the
second feed inlet 1025. The distribution conduit 1028 is positioned such that
it extends
along the longitudinal axis 50 which substantially coincides with the machine
direction
1092 along which the first web 1039 of cover sheet material moves. Preferably,
the
central midpoint of the distribution outlet 1030 (taken along the transverse
axis / cross-
machine direction 60) substantially coincides with the central midpoint of the
first
moving cover sheet 1039. The first and second flows 1047, 1048 of aqueous
calcined
gypsum slurry combine in the slurry distributor 1020 such that the combined
first and
second flows 1051 of aqueous calcined gypsum slurry pass through the
distribution
outlet 1030 in a distribution direction 1093 generally along the machine
direction 1092.
[00289] In some embodiments, the distribution conduit 1028 is positioned
such that it
is substantially parallel to the plane defines by the longitudinal axis 50 and
the
transverse axis 60 of the first web 1039 moving along the forming table. In
other
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
62
embodiments, the entry portion of the distribution conduit can be disposed
vertically
lower or higher than the distribution outlet 1030 relative to the first web
1039.
[00290] The combined first and second flows 1051 of aqueous calcined gypsum
slurry
are discharged from the slurry distributor 1020 upon the first moving web
1039. The
face skim coat/hard edge stream 1049 can be deposited from the mixer 1012 at a
point
upstream, relative to the direction of movement of the first moving web 1039
in the
machine direction 1092, of where the first and second flows 1047, 1048 of
aqueous
calcined gypsum slurry are discharged from the slurry distributor 1020 upon
the first
moving web 1039. The combined first and second flows 1047, 1048 of aqueous
calcined gypsum slurry can be discharged from the slurry distributor with a
reduced
momentum per unit width along the cross-machine direction relative to a
conventional
boot design to help prevent "washout" of the face skim coat/hard edge stream
1049
deposited on the first moving web 1039 (i.e., the situation where a portion of
the
deposited skim coat layer is displaced from its position upon the moving web
339 in
response to the impact of the slurry being deposited upon it).
[00291] The first and second flows 1047, 1048 of aqueous calcined gypsum
slurry
respectively passed through the first and second feed inlets 1024, 1025 of the
slurry
distributor 1020 can be selectively controlled with at least one flow-
modifying element
1023. For example, in some embodiments, the first and second flows 1047, 1048
of
aqueous calcined gypsum slurry are selectively controlled such that the
average
velocity of the first flow 1047 of aqueous calcined gypsum slurry passing
through the
first feed inlet 1024 and the average velocity of the second flow 1048 of
aqueous
calcined gypsum slurry passing through the second feed inlet 1025 are
substantially the
same.
[00292] In embodiments, the first flow 1047 of aqueous calcined gypsum slurry
is
passed at an average first feed velocity through the first feed inlet 1024 of
the slurry
distributor 1020. The second flow 1048 of aqueous calcined gypsum slurry is
passed at
an average second feed velocity through the second feed inlet 1025 of the
slurry
distributor 1020. The second feed inlet 1025 is in spaced relationship to the
first feed
inlet 1024. The first and second flows 1051 of aqueous calcined gypsum slurry
are
CA 02888273 2015-04-16
WO 2014/066211
PCT/U52013/065843
63
combined in the slurry distributor 1020. The combined first and second flows
1051 of
aqueous calcined gypsum slurry are discharged at an average discharge velocity
from a
distribution outlet 1030 of the slurry distributor 1020 upon the web 1039 of
cover sheet
material moving along a machine direction 1092. The average discharge velocity
is less
than the average first feed velocity and the average second feed velocity.
[00293] In some embodiments, the average discharge velocity is less than about
90%
of the average first feed velocity and the average second feed velocity. In
some
embodiments, the average discharge velocity is less than about 80% of the
average first
feed velocity and the average second feed velocity.
[00294] The combined first and second flows 1051 of aqueous calcined gypsum
slurry
are discharged from the slurry distributor 1020 through the distribution
outlet 1030. The
opening of the distribution outlet 1030 has a width extending along the
transverse axis
60 and sized such that the ratio of the width of the first moving web 1039 of
cover sheet
material to the width of the opening of the distribution outlet 1030 is within
a range
including and between about 1:1 and about 6:1. In some embodiments, the ratio
of the
average velocity of the combined first and second flows 1051 of aqueous
calcined
gypsum slurry discharging from the slurry distributor 1020 to the velocity of
the moving
web 1039 of cover sheet material moving along the machine direction 1092 can
be
about 2:1 or less in some embodiments, and from about 1:1 to about 2:1 in
other
embodiments.
[00295] The combined first and second flows 1051 of aqueous calcined gypsum
slurry
discharging from the slurry distributor 1020 form a spread pattern upon the
moving web
1039. At least one of the size and shape of the distribution outlet 1030 can
be adjusted,
which in turn can change the spread pattern.
[00296] Thus, slurry is fed into both feed inlets 1024, 1025 of the feed
conduit 1022
and then exits through the distribution outlet 1030 with an adjustable gap. A
converging
portion 1082 can provide a slight increase in the slurry velocity so as to
reduce
unwanted exit effects and thereby further improve flow stability at the free
surface.
Side-to-side flow variation and/or any local variations can be reduced by
performing
cross-machine (CD) profiling control at the discharge outlet 1030 using the
profiling
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
64
system. This distribution system can help prevent air-liquid slurry separation
in the
slurry resulting in a more uniform and consistent material delivered to the
forming table
1038.
[00297] A back skim coat stream 1053 (a layer of denser aqueous calcined
gypsum
slurry relative to at least one of the first and second flows 1047, 1048 of
aqueous
calcined gypsum slurry) can be applied to the second moving web 1043. The back
skim
coat stream 1053 can be deposited from the mixer 1012 at a point upstream,
relative to
the direction of movement of the second moving web 1043, of the back skim coat
roller
1037.
[00298] In other embodiments, the average velocity of the first and second
flows
1047, 1048 of aqueous calcined gypsum slurry are varied. In some embodiments,
the
slurry velocities at the feed inlets 1024, 1025 of the feed conduit 1022 can
oscillate
periodically between relatively higher and lower average velocities (at one
point in time
one inlet has a higher velocity than the other inlet, and then at a
predetermined point in
time vice versa) to help reduce the chance of buildup within the geometry
itself.
[00299] In embodiments, the first flow 1047 of aqueous calcined gypsum slurry
passing through the first feed inlet 1024 has a shear rate that is lower than
the shear
rate of the combined first and second flows 1051 discharging from the
distribution outlet
1030, and the second flow 1048 of aqueous calcined gypsum slurry passing
through the
second feed inlet 1025 has a shear rate that is lower than the shear rate of
the
combined first and second flows 1051 discharging from the distribution outlet
1030. In
embodiments, the shear rate of the combined first and second flows 1051
discharging
from the distribution outlet 1030 can be greater than about 150% of the shear
rate of the
first flow 1047 of aqueous calcined gypsum slurry passing through the first
feed inlet
1024 and/or the second flow 1048 of aqueous calcined gypsum slurry passing
through
the second feed inlet 1025, greater than about 175% in still other
embodiments, and
about double or greater in yet other embodiments. It should be understood that
the
viscosity of the first and second flows 1047, 1048 of aqueous calcined gypsum
slurry
and the combined first and second flows 1051 can be inversely related to the
shear rate
present at a given location such that as the shear rate goes up, the viscosity
decreases.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
[00300] In embodiments, the first flow 1047 of aqueous calcined gypsum slurry
passing through the first feed inlet 1024 has a shear stress that is lower
than the shear
stress of the combined first and second flows 1051 discharging from the
distribution
outlet 1030, and the second flow 1048 of aqueous calcined gypsum slurry
passing
through the second feed inlet 1025 has a shear stress that is lower than the
shear
stress of the combined first and second flows 1051 discharging from the
distribution
outlet 1030. In embodiments, the shear stress of the combined first and second
flows
1051 discharging from the distribution outlet 1030 can be greater than about
110% of
the shear rate of the first flow 1047 of aqueous calcined gypsum slurry
passing through
the first feed inlet 1024 and/or the second flow 1048 of aqueous calcined
gypsum slurry
passing through the second feed inlet 1025.
[00301] In embodiments, the first flow 1047 of aqueous calcined gypsum slurry
passing through the first feed inlet 1024 has a Reynolds number that is higher
than the
Reynolds number of the combined first and second flows 1051 discharging from
the
distribution outlet 1030, and the second flow 1048 of aqueous calcined gypsum
slurry
passing through the second feed inlet 1025 has a Reynolds number that is
higher than
the Reynolds number of the combined first and second flows 1051 discharging
from the
distribution outlet 1030. In embodiments, the Reynolds number of the combined
first
and second flows 1051 discharging from the distribution outlet 1030 can be
less than
about 90% of the Reynolds number of the first flow 1047 of aqueous calcined
gypsum
slurry passing through the first feed inlet 1024 and/or the second flow 1048
of aqueous
calcined gypsum slurry passing through the second feed inlet 1025, less than
about
80% in still other embodiments, and less than about 70% in still other
embodiments.
[00302] Referring to FIGS. 62 and 63, an embodiment of a Y-shaped flow
splitter
1100 suitable for use in a gypsum slurry mixing and dispensing assembly
constructed in
accordance with principles of the present disclosure is shown. The flow
splitter 1100
can be placed in fluid communication with a gypsum slurry mixer and a slurry
distributor
such that the flow splitter 1100 receives a single flow of aqueous calcined
gypsum slurry
from the mixer and discharges two separate flows of aqueous calcined gypsum
slurry
therefrom to the first and second feed inlets of the slurry distributor. One
or more flow-
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
66
modifying elements can be disposed between the mixer and the flow splitter
1100
and/or between one or both of the delivery branches leading between the
splitter 1100
and the associated slurry distributor.
[00303] The flow splitter 1100 has a substantially circular inlet 1102
disposed in a
main branch 1103 adapted to receive a single flow of slurry and a pair of
substantially
circular outlets 1104, 1106 disposed respectively in first and second outlet
branches
1105, 1107 that allow two flows of slurry to discharge from the splitter 1100.
The cross-
sectional areas of the openings of the inlet 1102 and the outlets 1104, 1106
can vary
depending on the desired flow velocity. In embodiments where the cross-
sectional
areas of the openings of outlet 1104, 1106 are each substantially equal to
cross-
sectional area of the opening of the inlet 1102, the flow velocity of the
slurry discharging
from each outlet 1104, 1106 can be reduced to about 50% of the velocity of the
single
flow of slurry entering the inlet 1102 where the volumetric flow rate through
the inlet
1102 and both outlets 1104, 1106 is substantially the same.
[00304] In some embodiments, the diameter of the outlets 1104, 1106 can be
made
smaller than the diameter of the inlet 1102 in order to maintain a relatively
high flow
velocity throughout the splitter 1100. In embodiments where the cross-
sectional areas
of the openings of the outlets 1104, 1106 are each smaller than the cross-
sectional area
of the opening of the inlet 1102, the flow velocity can be maintained in the
outlets 1104,
1106 or at least reduced to a lesser extent than if the outlets 1104, 1106 and
the inlet
1102 all have substantially equal cross-sectional areas. For example, in some
embodiments, the flow splitter 1100 has the inlet 1102 has an inner diameter
(ID1) of
about 3 inches, and each outlet 1104, 1106 has an ID2 of about 2.5 inches
(though
other inlet and outlet diameters can be used in other embodiments). In an
embodiment
with these dimensions at a line speed of 350 fpm, the smaller diameter of the
outlets
1104, 1106 causes the flow velocity in each outlet to be reduced by about 28%
of the
flow velocity of the single flow of slurry at the inlet 1102.
[00305] The flow splitter 1100 can includes a central contoured portion 1114
and a
junction 1120 between the first and second outlet branches 1105, 1107. The
central
contoured portion 1114 creates a restriction 1108 in the central interior
region of the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
67
flow splitter 1100 upstream of the junction 1120 that helps promote flow to
the outer
edges 1110, 1112 of the splitter to reduce the occurrence of slurry buildup at
the
junction 1120. The shape of the central contoured portion 1114 results in
guide
channels 1111, 1113 adjacent the outer edges 1110, 1112 of the flow splitter
1100. The
restriction 1108 in the central contoured portion 1114 has a smaller height H2
than the
height H3 of the guide channels 1111, 1113. The guide channels 1111, 1113 have
a
cross-sectional area that is larger than the cross-sectional area of the
central restriction
1108. As a result, the flowing slurry encounters less flow resistance through
the guide
channels 1111, 1113 than through the central restriction 1108, and flow is
directed
toward the outer edges of the splitter junction 1120.
[00306] The junction 1120 establishes the openings to the first and second
outlet
branches 1105, 1107. The junction 1120 is made up of a planar wall surface
1123 that
is substantially perpendicular to an inlet flow direction 1125.
[00307] Referring to FIG. 64, in some embodiments, an automatic device 1150
for
squeezing the splitter 1100 at adjustable and regular time intervals can be
provided to
prevent solids building up inside the splitter 1100. In some embodiments, the
squeezing apparatus 1150 can include a pair of plates 1152, 1154 disposed on
opposing sides 1142, 1143 of the central contoured portion 1114. The plates
1152,
1154 are movable relative to each other by a suitable actuator 1160. The
actuator 1160
can be operated either automatically or selectively to move the plates 1152,
1154
together relative to each other to apply a compressive force upon the splitter
1100 at the
central contoured portion 1114 and the junction 1120.
[00308] When the squeezing apparatus 1150 squeezes the flow splitter, the
squeezing action applies compressive force to the flow splitter 1100, which
flexes
inwardly in response. This compressive force can help prevent buildup of
solids inside
the splitter 1100 which may disrupt the substantially equally split flow to
the slurry
distribution through the outlets 1104, 1106. In some embodiments, the
squeezing
apparatus 1150 is designed to automatically pulse through the use of a
programmable
controller operably arranged with the actuators. The time duration of the
application of
the compressive force by the squeezing apparatus 1150 and/or the interval
between
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
68
pulses can be adjusted. Furthermore, the stroke length that the plates 1152,
1154
travel with respect to each other in a compressive direction can be adjusted.
[00309] In an embodiment, a method of preparing a cementitious product can be
performed using a slurry distributor constructed according to principles of
the present
disclosure. A flow of aqueous cementitious slurry is discharged from a mixer.
A flow of
aqueous cementitious slurry is passed at an average feed velocity through a
feed inlet
of a slurry distributor along a first feed flow axis. The flow of aqueous
cementitious
slurry is passed into a bulb portion of the slurry distributor. The bulb
portion has an area
of expansion with a cross-sectional flow area that is greater than a cross-
sectional flow
area of an adjacent area upstream from the area of expansion relative to a
flow
direction from the feed inlet. The bulb portion is configured to reduce the
average
velocity of the flow of aqueous cementitious slurry moving from the feed inlet
through
the bulb portion. The shaped duct has a convex interior surface in confronting
relationship with first feed flow axis such that the flow of aqueous
cementitious slurry
moves in radial flow in a plane substantially perpendicular to the first feed
flow axis.
The flow of aqueous cementitious slurry is passed into a transition segment
extending
along a second feed flow axis, which is in non-parallel relationship with the
first feed
flow axis.
[00310] The flow of aqueous cementitious slurry is passed into a distribution
conduit.
The distribution conduit includes a distribution outlet extending a
predetermined
distance along a transverse axis, which is substantially perpendicular to the
longitudinal
axis.
[00311] In embodiments, the flow of slurry moving through a region adjacent
the
convex interior surface and adjacent at least one of the lateral sidewalls
toward the
distribution outlet has a swirl motion (Sm) from about zero to about 10, and
from about
0.5 to about 5 in other embodiments. In embodiments, the flow of slurry moving
through
the region adjacent the convex interior surface and adjacent at least one of
the lateral
sidewalls toward the distribution outlet has a swirl angle (Sm) from about 0
to about 84 .
[00312] In embodiments, the flow of aqueous cementitious slurry is passed
through a
flow stabilization region adapted to reduce an average feed velocity of the
flow of
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
69
aqueous cementitious slurry entering the feed inlet and moving to the
distribution outlet.
The flow of aqueous cementitious slurry is discharged from the distribution
outlet at an
average discharge velocity that is at least twenty percent less than the
average feed
velocity.
[00313] In another embodiment, a method of preparing a cementitious product
includes discharging a flow of aqueous cementitious slurry from a mixer. The
flow of
aqueous cementitious slurry is passed through an entry portion of a
distribution conduit
of a slurry distributor. The flow of aqueous cementitious slurry is discharged
from a
distribution outlet of the slurry distributor upon a web of cover sheet
material moving
along a machine direction. A wiper blade is reciprocally moved over a clearing
path
along a bottom surface of the distribution conduit between a first position
and a second
position to clear aqueous cementitious slurry therefrom. The clearing path is
disposed
adjacent the distribution outlet.
[00314] In embodiments, the distribution conduit extends generally along a
longitudinal axis between the entry portion and the distribution outlet. The
wiper blade
reciprocally moves longitudinally along the clearing path.
[00315] In embodiments, the wiper blade moves in a clearing direction from the
first
position to the second position over a wiping stroke, and the wiper blade
moves in an
opposing, return direction from the second position to the first position over
a return
stroke. The wiper blade reciprocally moves such that the time to move over the
wiping
stroke is substantially the same as the time to move over the return stroke.
[00316] In embodiments, the wiper blade moves in a clearing direction from the
first
position to the second position over a wiping stroke, and the wiper blade
moves in an
opposing, return direction from the second position to the first position over
a return
stroke. The wiper blade reciprocally moves between the first position and the
second
position in a cycle having a sweep period. The sweep period includes a wiping
portion
comprising the time to move over the wiping stroke, a returning portion
comprising the
time to move over the return stroke, and an accumulation delay portion
comprising a
predetermined period of time in which the wiper blade remains in the first
position. In
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
embodiments, the wiping portion is substantially the same as the returning
portion. In
embodiments, the accumulation delay portion is adjustable.
[00317] In still another embodiment, a method of preparing a cementitious
product
includes discharging a flow of aqueous cementitious slurry from a mixer. The
flow of
aqueous cementitious slurry is passed through an entry portion of a
distribution conduit
of a slurry distributor. The flow of aqueous cementitious slurry is discharged
from an
outlet opening of a distribution outlet of the slurry distributor upon a web
of cover sheet
material moving along a machine direction. The distribution outlet extends a
predetermined distance along a transverse axis, which is substantially
perpendicular to
the longitudinal axis. The outlet opening has a width, along the transverse
axis, and a
height, along a vertical axis mutually perpendicular to the longitudinal axis
and the
transverse axis. A portion of the distribution conduit adjacent the
distribution outlet is
compressively engaged to vary the shape and/or size of the outlet opening. In
embodiments, the distribution conduit is compressively engaged by a profiling
mechanism such that the flow of aqueous cementitious slurry is discharged from
the
outlet opening with an increased spread angle relative to the machine
direction.
[00318] In embodiments, the distribution conduit is compressively engaged by a
profiling mechanism having a profiling member in contacting relationship with
the
distribution conduit. The profiling member is movable over a range of travel
such that
the profiling member is in a range of positions over which the profiling
member is in
increasing compressive engagement with the distribution conduit. In
embodiments the
method includes moving the profiling member along the vertical axis to adjust
the size
and/or shape of the outlet opening. In embodiments the method includes moving
the
profiling member such that the profiling member translates along at least one
axis
and/or rotates about at least one axis to adjust the size and/or shape of the
outlet
opening.
[00319] Embodiments of a slurry distributor, a cementitious slurry mixing and
dispensing assembly, and methods of using the same are provided herein which
can
provide many enhanced process features helpful in manufacturing cementitious
products, such as gypsum wallboard in a commercial setting. A slurry
distributor
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
71
constructed in accordance with principles of the present disclosure can
facilitate the
spreading of aqueous calcined gypsum slurry upon a moving web of cover sheet
material as it advances past a mixer at the wet end of the manufacturing line
toward a
forming station.
[00320] A gypsum slurry mixing and dispensing assembly constructed in
accordance
with principles of the present disclosure can split a flow of aqueous calcined
gypsum
slurry from a mixer into two separate flows of aqueous calcined gypsum slurry
which
can be recombined downstream in a slurry distributor constructed in accordance
with
principles of the present disclosure to provide a desired spreading pattern.
The design
of the dual inlet configuration and the distribution outlet can allow for
wider spreading of
more viscous slurry in the cross-machine direction over the moving web of
cover sheet
material. The slurry distributor can be adapted such that the two separate
flows of
aqueous calcined gypsum slurry enter a slurry distributor along feed inlet
directions
which include a cross-machine direction component, are re-directed inside the
slurry
distributor such that the two flows of slurry are moving in substantially a
machine
direction, and are recombined in the distributor in a way to enhance the cross-
direction
uniformity of the combined flows of aqueous calcined gypsum slurry being
discharged
from the distribution outlet of the slurry distributor to help reduce mass
flow variation
over time along the transverse axis or cross machine direction. Introducing
the first and
second flows of aqueous calcined gypsum slurry in first and second feed
directions that
include a cross-machine directional component can help the re-combined flows
of slurry
discharge from the slurry distributor with a reduced momentum and/or energy.
[00321] The interior flow cavity of the slurry distributor can be configured
such that
each of the two flows of slurry move through the slurry distributor in a
streamline flow.
The interior flow cavity of the slurry distributor can be configured such that
each of the
two flows of slurry move through the slurry distributor with minimal or
substantially no
air-liquid slurry phase separation. The interior flow cavity of the slurry
distributor can be
configured such that each of the two flows of slurry move through the slurry
distributor
substantially without undergoing a vortex flow path.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
72
[00322] A gypsum slurry mixing and dispensing assembly constructed in
accordance
with principles of the present disclosure can include flow geometry upstream
of the
distribution outlet of the slurry distributor to reduce the slurry velocity in
one or multiple
steps. For example, a flow splitter can be provided between the mixer and the
slurry
distributor to reduce the slurry velocity entering the slurry distributor. As
another
example, the flow geometry in the gypsum slurry mixing and dispensing assembly
can
include areas of expansion upstream and within the slurry distributor to slow
down the
slurry so it is manageable when it is discharged from the distribution outlet
of the slurry
distributor.
[00323] The geometry of the distribution outlet can also help control the
discharge
velocity and momentum of the slurry as it is being discharged from the slurry
distributor
upon the moving web of cover sheet material. The flow geometry of the slurry
distributor can be adapted such that the slurry discharging from the
distribution outlet is
maintained in substantially a two-dimensional flow pattern with a relatively
small height
in comparison to the wider outlet in the cross-machine direction to help
improve stability
and uniformity.
[00324] The relatively wide discharge outlet yields a momentum per unit width
of the
slurry being discharged from the distribution outlet that is lower than the
momentum per
unit width of a slurry discharged from a conventional boot under similar
operating
conditions. The reduced momentum per unit width can help prevent washout of a
skim
coat of a dense layer applied to the web of cover sheet material upstream from
the
location where the slurry is discharged from the slurry distributor upon the
web.
[00325] In the situation where a conventional boot outlet is 6 inches wide and
2 inches
thick is used, the average velocity of the outlet for a high volume product
can be about
761 ft/min. In embodiments where the slurry distributor constructed in
accordance with
principles of the present disclosure includes a distribution outlet having an
opening that
is 24 inches wide and 0.75 inches thick, the average velocity can be about 550
ft/min.
The mass flow rate is the same for both devices at 3,437 lb/min. The momentum
of the
slurry (mass flow rate*average velocity) for both cases would be ¨2,618,000
and
1,891,000 lb.ft/min2 for the conventional boot and the slurry distributor,
respectively.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
73
Dividing the respective calculated momentum by the widths of the conventional
boot
outlet and the slurry distributor outlet, the momentum per unit width of the
slurry
discharging from the convention boot is 402,736 (1b.ft/min2)/(inch across boot
width),
and the momentum per unit width of the slurry discharging from the slurry
distributor
constructed in accordance with principles of the present disclosure is 78,776
(1b.ft/min2)/(inch across slurry distributor width). In this case, the slurry
discharging from
the slurry distributor has about 20% of the momentum per unit width compared
to the
conventional boot.
[00326] A slurry distributor constructed in accordance with principles of the
present
disclosure can achieve a desired spreading pattern while using an aqueous
calcined
gypsum slurry over a broad range of water-stucco ratios, including a
relatively low WSR
or a more conventional WSR, such as, a water-to-calcined gypsum ratio from
about 0.4
to about 1.2, for example, below 0.75 in some embodiments, and between about
0.4
and about 0.8 in other embodiments. Embodiments of a slurry distributor
constructed in
.. accordance with principles of the present disclosure can include internal
flow geometry
adapted to generate controlled shear effects upon the first and second flows
of aqueous
calcined gypsum slurry as the first and second flows advance from the first
and second
feed inlets through the slurry distributor toward the distribution outlet. The
application of
controlled shear in the slurry distributor can selectively reduce the
viscosity of the slurry
as a result of being subjected to such shear. Under the effects of controlled
shear in the
slurry distributor, slurry having a lower water-stucco ratio can be
distributed from the
slurry distributor with a spread pattern in the cross-machine direction
comparable to
slurries having a conventional WSR.
[00327] The interior flow geometry of the slurry distributor can be adapted to
further
accommodate slurries of various water-stucco ratios to provide increase flow
adjacent
the boundary wall regions of the interior geometry of the slurry distributor.
By including
flow geometry features in the slurry distributor adapted to increase the
degree of flow
around the boundary wall layers, the tendency of slurry to re-circulate in the
slurry
distributor and/or stop flowing and set therein is reduced. Accordingly, the
build up of
set slurry in the slurry distributor can be reduced as a result.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
74
[00328] A slurry distributor constructed in accordance with principles of the
present
disclosure can include a profile system mounted adjacent the distribution
outlet to alter
a cross machine velocity component of the combined flows of slurry discharging
from
the distribution outlet to selectively control the spread angle and spread
width of the
slurry in the cross machine direction on the substrate moving down the
manufacturing
line toward the forming station. The profile system can help the slurry
discharged from
the distribution outlet achieve a desired spread pattern while being less
sensitive to
slurry viscosity and WSR. The profile system can be used to change the flow
dynamics
of the slurry discharging from the distribution outlet of the slurry
distributor to guide
slurry flow such that the slurry has more uniform velocity in the cross-
machine direction.
Using the profile system can also help a gypsum slurry mixing and dispensing
assembly
constructed in accordance with principles of the present disclosure be used in
a gypsum
wallboard manufacturing setting to produce wallboard of different types and
volumes.
[00329] Thus, in an embodiment, a slurry distributor comprises a distribution
conduit
extending generally along a longitudinal axis and includes an entry portion
and a
distribution outlet in fluid communication with the entry portion. The
distribution outlet
extends a predetermined distance along a transverse axis. The transverse axis
is
substantially perpendicular to the longitudinal axis. The distribution outlet
includes an
outlet opening having a width, along the transverse axis, and a height, along
a vertical
axis mutually perpendicular to the longitudinal axis and the transverse axis.
A profiling
mechanism including a profiling member is in contacting relationship with the
distribution conduit. The profiling member is movable over a range of travel
such that
the profiling member is in a range of positions over which the profiling
member is in
increasing compressive engagement with a portion of the distribution conduit
adjacent
the distribution outlet to vary the shape and/or size of the outlet opening.
[00330] In another embodiment, the outlet opening of the distribution
outlet has a
width-to-height ratio of about 4 or more.
[00331] In another embodiment, the outlet opening of the distribution
outlet has a
width along the transverse axis. The profiling member has a width extending a
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
predetermined second distance along the transverse axis. The width of the
outlet
opening is larger than the width of the profiling member. The profiling member
is
positioned such that a pair of lateral portions of the distribution outlet are
in offset
relationship to the profiling member.
[00332] In another embodiment, the profiling member of the slurry
distributor is
movable along the vertical axis.
[00333] In another embodiment, the profiling member of the slurry distributor
member
has at least two degrees of freedom.
[00334] In another embodiment, the profiling member of the slurry
distributor is
translatable along at least one axis and rotatable about at least one pivot
axis.
[00335] In another embodiment, the profiling member of the slurry
distributor is
translatable along the vertical axis and rotatable about a pivot axis that is
substantially
parallel to the longitudinal axis. The profiling member is rotatable about the
pivot axis
over an arc length such that the profiling member is in a range of positions
over which
the profiling member is in variable compressive engagement with the portion of
the
distribution conduit across the transverse axis such that the height of the
outlet opening
varies along the transverse axis.
[00336] In another embodiment, the profiling member of the slurry distributor
includes
a support assembly having a stationary support member and a pivotal support
member.
The pivotal support member is rotatable about the pivot axis over the arc
length with
respect to the stationary support member. The pivotal support member supports
the
profiling member.
[00337] In another embodiment, the profiling member of the slurry
distributor is
rotatable about a pivot axis over an arc length such that the profiling member
is in a
range of positions over which the profiling member is in variable compressive
engagement with the portion of the distribution conduit across the transverse
axis such
that the height of the outlet opening varies along the transverse axis.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
76
[00338] In another embodiment, the profiling member of the slurry distributor
includes
a support assembly, an engagement segment extending generally longitudinally
and
transversely and a translation adjustment rod extending generally vertically
from the
engagement segment. The translation adjustment rod of the profiling member is
movably secured to the support assembly such that the profiling member is
movable
over a range of vertical positions.
[00339] In another embodiment, the support assembly includes a clamp mechanism
adapted to selectively engage the translation adjustment rod to secure the
profiling
member in a selected one of the range of vertical positions.
[00340] In another embodiment, the support assembly is adapted to rotatably
support
the profiling member such that the profiling member is rotatable about a pivot
axis over
a range of positions along an arc length.
[00341] In another embodiment, the support assembly includes a stationary
support
member and a pivotal support member. The pivotal support member is rotatable
about
the pivot axis over the arc length with respect to the stationary support
member. The
pivotal support member supports the profiling member.
[00342] In another embodiment, the support assembly includes a rotation
adjustment
rod extending between the stationary support member and the pivotal support
member.
The rotation adjustment rod is movably secured to the stationary support
member such
that moving the rotation adjustment rod with respect to the stationary member
pivots the
pivotal support member about the pivot axis with respect to the stationary
support
member.
[00343] In another embodiment, the support assembly includes a clamp mechanism
adapted to selectively engage the rotation adjustment rod to secure the
profiling
member in a selected one of the range of positions along the arc length.
[00344] In another embodiment, a cementitious slurry mixing and dispensing
assembly comprises: a mixer adapted to agitate water and a cementitious
material to
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
77
form an aqueous cementitious slurry and a slurry distributor in fluid
communication with
the mixer. The slurry distributor includes a distribution conduit extending
generally along
a longitudinal axis and including an entry portion and a distribution outlet
in fluid
communication with the entry portion. The distribution outlet extends a
predetermined
distance along a transverse axis. The transverse axis is substantially
perpendicular to
the longitudinal axis. The distribution outlet includes an outlet opening
having a width,
along the transverse axis, and a height, along a vertical axis mutually
perpendicular to
the longitudinal axis and the transverse axis. The slurry distributor also
includes a
profiling mechanism including a profiling member in contacting relationship
with the
distribution conduit, the profiling member movable over a range of travel such
that the
profiling member is in a range of positions over which the profiling member is
in
increasing compressive engagement with a portion of the distribution conduit
adjacent
the distribution outlet to vary the shape and/or size of the outlet opening.
[00345] In another embodiment, the cementitious slurry mixing and dispensing
assembly further comprises a distributor support member supporting the
distribution
conduit. The profiling mechanism of the slurry distributor includes a support
assembly
having a stationary support member and a pivotal support member. The
stationary
support member is connected to the distributor support member. The pivotal
support
member is rotatable about a pivot axis over an arc length with respect to the
stationary
support member, the pivotal support member supporting the profiling member.
[00346] In another embodiment, the cementitious slurry mixing and dispensing
assembly further comprises a delivery conduit disposed between and in fluid
communication with the mixer and the slurry distributor, a flow-modifying
element
associated with the delivery conduit and adapted to control a flow of the
aqueous
cementitious slurry from the mixer, and an aqueous foam supply conduit in
fluid
communication with at least one of the mixer and the delivery conduit.
[00347] In another embodiment, the cementitious slurry mixing and dispensing
comprises a slurry distributor including a feed conduit including a first
entry segment
with a first feed inlet and a second entry segment with a second feed inlet
disposed in
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
78
spaced relationship to the first feed inlet. The entry portion of the
distribution conduit IS
in fluid communication with the first and second feed inlets of the feed
conduit. The first
feed inlet is adapted to receive a first flow of aqueous cementitious slurry
from the
mixer. The second feed inlet adapted to receive a second flow of aqueous
cementitious
slurry from the mixer, and the distribution outlet in fluid communication with
both the first
and the second feed inlets and adapted such that combined first and second
flows of
aqueous cementitious slurry discharge from the slurry distributor through the
distribution
outlet.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
79
[00348] In another embodiment, the gypsum slurry mixing and dispensing
assembly
further comprises a delivery conduit disposed between and in fluid
communication with
the mixer and the slurry distributor, the delivery conduit including a main
delivery trunk
and first and second delivery branches and a flow splitter joining the main
delivery trunk
and the first and second delivery branches, the flow splitter disposed between
the main
delivery trunk and the first delivery branch and between the main delivery
trunk and the
second delivery branch. The first delivery branch is in fluid communication
with the first
feed inlet of the slurry distributor, and the second delivery branch is in
fluid
communication with the second feed inlet of the slurry distributor.
[00349] In another embodiment, a method of preparing a cementitious product
comprises: (a) discharging a flow of aqueous cementitious slurry from a mixer;
(b)
passing the flow of aqueous cementitious slurry through an entry portion of a
distribution
conduit of a slurry distributor; (c) discharging the flow of aqueous
cementitious slurry
from an outlet opening of a distribution outlet of the slurry distributor upon
a web of
cover sheet material moving along a machine direction, the distribution outlet
extending
a predetermined distance along a transverse axis, the transverse axis being
substantially perpendicular to the longitudinal axis, the outlet opening
having a width,
along the transverse axis, and a height, along a vertical axis mutually
perpendicular to
the longitudinal axis and the transverse axis; and (d) compressively engaging
a portion
of the distribution conduit adjacent the distribution outlet to vary the shape
and/or size of
the outlet opening.
[00350] In another embodiment, the method of preparing a cementitious product
of
comprises the distribution conduit being compressively engaged by a profiling
mechanism such that the flow of aqueous cementitious slurry is discharged from
the
outlet opening with an increased spread angle relative to the machine
direction.
[00351] In another embodiment, the method of preparing a cementitious product
comprises the distribution conduit being compressively engaged by a profiling
mechanism having a profiling member in contacting relationship with the
distribution
conduit. The profiling member is movable over a range of travel such that the
profiling
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
member is in a range of positions over which the profiling member is in
increasing
compressive engagement with the distribution conduit.
[00352] In another embodiment, the method of preparing a cementitious product
further comprises moving the profiling member along the vertical axis to
adjust the size
and/or shape of the outlet opening.
[00353] In another embodiment, the method of preparing a cementitious product
further comprises moving the profiling member such that the profiling member
translates
along at least one axis and/or rotates about at least one axis to adjust the
size and/or
shape of the outlet opening.
EXAMPLES
[00354] Referring to FIG. 65, the geometry and flow characteristics of an
embodiment
of a slurry distributor constructed in accordance with principles of the
present disclosure
were evaluated in Examples 1-3. A top plan view of a half portion 1205 of a
slurry
distributor is shown in FIG. 65. The half portion 1205 of the slurry
distributor includes a
half portion 1207 of a feed conduit 320 and a half portion 1209 of a
distribution conduit
328. The half portion 1207 of the feed conduit 322 includes a second feed
inlet 325
defining a second opening 335, a second entry segment 337, and a half portion
1211 of
a bifurcated connector segment 339. The half portion 1209 of the distribution
conduit
328 includes a half portion 1214 of an entry portion 352 of the distribution
conduit 328
and a half portion 1217 of a distribution outlet 330.
[00355] It should be understood that another half portion of a slurry
distributor, which
is a mirror image of the half portion 1205 of FIG. 65, can be integrally
joined and aligned
with the half portion 1205 of FIG. 65 at a transverse central midpoint 387 of
the
distribution outlet 330 to form a slurry distributor which is substantially
similar to the
slurry distributor 420 of FIG. 15. Accordingly, the geometry and flow
characteristics
described below are equally applicable to the mirror image half portion of the
slurry
distributor as well.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
81
[00356] Referring to FIG. 72, the geometry and flow characteristics of another
embodiment of a slurry distributor 2020 constructed in accordance with
principles of the
present disclosure were evaluated in Examples 4-6. The slurry distributor 2020
shown
in FIG. 72 is substantially the same as the slurry distributor 1420 of FIG.
34. The flow
characteristics of the slurry distributor 2020 of FIG. 72 using a profiling
mechanism
constructed in accordance with principles of the present disclosure were
evaluated in
Example 7. The profiling mechanism evaluated in Example 7 is substantially the
same
as the profiling mechanism 1432 of FIG. 22.
EXAMPLE 1
[00357] In this Example and referring to FIG. 65, the particular geometry
of the half
portion 1205 of the slurry distributor was evaluated at sixteen different
locations L1-16
between a first location L1 at the second feed inlet 325 and a sixteenth
location L16 at a
half portion 1207 of the distribution outlet 330. Each location L1-16
represents a cross-
sectional slice of the half portion 1205 of the slurry distributor as
indicated by the
corresponding line. A flow line 1212 along the geometric center of each cross-
sectional
slice was used to determine the distance between adjacent locations L1.16. The
eleventh location L11 corresponds to the half portion 1214 of the entry
portion 352 of the
distribution conduit 328 which corresponds to an opening 342 of a second feed
outlet
345 of the half portion 1207 of the feed conduit 320. Accordingly, the first
through the
tenth locations L1_10 are taken in the half portion 1207 of the feed conduit
320, and the
eleventh through the sixteenth locations are taken in the half portion 1209 of
the
distribution conduit 328.
[00358] For each location L1-16, the following geometric values were
determined: the
distance along the flow line 1212 between the second feed inlet 325 and the
particular
location L1-16; the cross-sectional area of the opening at the location 1-
1_16; the perimeter
of the location L1_16; and the hydraulic diameter of the location L1_16. The
hydraulic
diameter was calculated using the following formula:
Dhyd = 4 x A / P (Eq. 1)
where Dhyd is the hydraulic diameter,
A is the area of the particular location L1-16, and
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
82
P is the perimeter of the particular location L1-16.
Using the inlet conditions, the dimensionless values for each location L1-16
can be
determined to describe the interior flow geometry, as shown in Table 1. Curve-
fit
equations were used to describe the dimensionless geometry of the half portion
1205 of
the slurry distributor in FIG. 66, which shows the dimensionless distance from
inlet
versus the dimensionless area and the hydraulic diameter.
[00359] The analysis of the dimensionless values for each location L1-16 shows
that
the cross sectional flow area increases from the first location L1 at the
second feed inlet
325 to the eleventh location L11 at the half portion 1214 of the entry portion
352 (also the
opening 342 of the second feed outlet 345). In the exemplary embodiment, the
cross-
sectional flow area at the half portion 1214 of the entry portion 352 is about
1/3 larger
than the cross-sectional flow area at the second feed inlet 325. Between the
first
location L1 and the eleventh location L11, the cross-sectional flow area of
the second
entry segment 337 and the second shaped duct 339 varies from location to
location L1_
1. In this region, at least two adjacent locations L6, L7 are configured such
that the
location L7 located further from the second feed inlet 325 has a cross
sectional flow
area that is smaller than the adjacent location L6 that is closer to the
second feed inlet
325.
1003601 Between the first location L1 and the eleventh location L11, in the
half portion
1207 of the feed conduit 322 there is an area of expansion (e.g., L4_6) having
a cross-
sectional flow area that is greater than a cross-sectional flow area of an
adjacent area
(e.g., L3) upstream from the area of expansion in a direction from the second
inlet 335
toward the half portion 1217 of the distribution outlet 330. The second entry
segment
337 and the second shaped duct 341 have a cross section that varies along the
direction of flow 1212 to help distribute the second flow of slurry moving
therethrough.
1003611 The cross sectional area decreases from the eleventh location L11 at
the half
portion 1214 of the entry portion 352 of the distribution conduit 328 to the
sixteenth
location L16 at the half portion 1217 of the distribution outlet 330 of the
distribution
conduit 328. In the exemplary embodiment, the cross-sectional flow area of the
half
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
83
portion 1214 of an entry portion 352 is about 95% of that of the half portion
1217 of the
distribution outlet 330.
[00362] The cross-sectional flow area at the first location L1 at the second
feed inlet
325 is smaller than the cross-sectional flow area at the sixteenth location
L16 at the half
portion 1217 of the distribution outlet 330 of the distribution conduit 328.
In the
exemplary embodiment, the cross-sectional flow area at the half portion 1217
of the
distribution outlet 330 of the distribution conduit 328 is about 1/4 larger
than the cross-
sectional flow area at the second feed inlet 325.
[00363] The hydraulic diameter decreases from the first location L1 at the
second feed
inlet 325 to the eleventh location L11 at the half portion 1214 of the entry
portion 352 of
the distribution conduit 328. In the exemplary embodiment, the hydraulic
diameter at
the half portion 1214 of the entry portion 352 of the distribution conduit 328
is about 1/2
the hydraulic diameter at the second feed inlet 325.
[00364] The hydraulic diameter decreases from the eleventh location L11 at the
half
portion 1214 of an entry portion 352 of the distribution conduit 328 to the
sixteenth
location L16 at the half portion 1217 of the distribution outlet 330 of the
distribution
conduit 328. In the exemplary embodiment, the hydraulic diameter of the half
portion
1217 of the distribution outlet 330 of the distribution conduit 328 is about
95% of that of
the half portion 1214 of the entry portion 352 of the distribution conduit
328.
[00365] The hydraulic diameter at the first location L1 at the second inlet
325 is larger
than the hydraulic diameter at the sixteenth location L16 at the half portion
1217 of the
distribution outlet 330 of the distribution conduit 328. In the exemplary
embodiment, the
hydraulic diameter at the half portion 1217 of the distribution outlet 330 of
the
distribution conduit 328 is less than about half of that of the second feed
inlet 325.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
84
TABLE I - GEOMETRY
Dimensionless
Location Distance Area Perimeter Hydraulic
From Dia.
Inlet
L1 0.00 1.00 1.00 1.00
L2 0.07 1.00 1.00 1.00
L3 0.14 0.91 0.98 0.93
L4 0.20 1.01 1.07 0.94
L5 0.27 1.18 1.24 0.95
L6 0.34 1.25 1.45 0.87
L7 0.41 1.16 1.68 0.69
L8 0.47 1.13 1.93 0.59
L9 0.54 1.23 2.20 0.56 .
L10 0.61 1.35 2.47 0.55
L11 0.68 1.33 2.73 0.49
L12 0.75 1.28 2.70 0.47
L13 0.81 1.27 2.68 0.48
L14 0.88 1.26 2.67 0.47
L15 0.95 1.26 2.67 0.47
L16 1.00 1.26 2.67 0.47
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
EXAMPLE 2
[00366] In this Example, the half portion 1205 of the slurry distributor of
FIG. 65 was
used to model the flow of gypsum slurry therethrough under different flow
conditions.
For all flow conditions, the density (p) of the aqueous gypsum slurry was set
at 1,000
kg/m3. Aqueous gypsum slurry is a shear-thinning material such that as shear
is
applied to it, its viscosity can decrease. The viscosity (p) Pa.s of the
gypsum slurry was
calculated using the Power Law Fluid Model which has the following equation:
p = K2> n-1 (Eq. 2)
where,
K is a constant,
2% is the shear rate, and
n is a constant equal to 0.133 in this case.
[00367] In a first flow condition, the gypsum slurry has a viscosity K
factor of 50 in the
Power Law model and enters the second feed inlet 325 at 2.5 m/s. A
computational
fluid dynamics technique with a finite volume method was used to determine
flow
characteristics in the distributor. At each location L1-16, the following flow
characteristics
were determined: area-weighted average velocity (U), area-weighted average
shear
rate (22), viscosity calculated using the Power Law Model (Eq. 2), shear
stress, and
Reynolds Number (Re).
[00368] The shear stress was calculated using the following equation:
Shear stress =px (Eq. 3)
where
p is the viscosity calculated using the Power Law Model (Eq. 2), and
2% is the shear rate.
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
86
[00369] The Reynolds Number was calculated using the following equation:
Re==pxUxDhydip (Eq. 4)
where
p is the density of the gypsum slurry,
U is the area-weighted average velocity,
Dhyd is the hydraulic diameter, and
p is the viscosity calculated using the Power Law Model (Eq. 2).
[00370] In a second flow condition case, the feed velocity of the gypsum
slurry into
the second feed inlet 325 was increased to 3.55 m/s. All other conditions were
the
same as in the first flow condition of this Example. The dimensional values
for the
mentioned flow characteristics at each location L1_16 for both the first flow
condition
where the inlet velocity is 2.5 m/s and the second flow condition where the
inlet velocity
is 3.55 m/s were modeled. Using the inlet conditions, dimensionless values of
the flow
characteristics for each location L1.16 were determined, as shown in Table II.
[00371] For both flow conditions where K was set equal to 50, the average
velocity
was reduced from the first location Li at the second feed inlet 325 to the
sixteenth
location L16 at the half portion 1217 of the distribution outlet 330 of the
distribution
conduit 328. In the illustrated embodiment, the average velocity was reduced
by about
1/5, as shown in FIG. 67.
[00372] For both flow conditions, the shear rate increased from the first
location Li at
the second feed inlet 325 to the sixteenth location L16 at the half portion
1217 of the
distribution outlet 330 of the distribution conduit 328. In the illustrated
embodiment, the
shear rate approximately doubled from the first location Li at the second feed
inlet 325
to the sixteenth location L16 at the half portion 1217 of the distribution
outlet 330 of the
distribution conduit 328, as shown in FIG. 68.
[00373] For both flow conditions, the calculated viscosity was reduced from
the first
location Li at the second feed inlet 325 to the sixteenth location L16 at the
half portion
1217 of the distribution outlet 330 of the distribution conduit 328. In the
illustrated
embodiment, the calculated viscosity was reduced from the first location Li at
the
second feed inlet 325 to the sixteenth location L16 at the half portion 1217
of the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
87
distribution outlet 330 of the distribution conduit 328 by about half, as
illustrated in FIG.
69.
[00374] For both flow conditions in FIG. 70, the shear stress increased from
the first
location Li at the second feed inlet 325 to the sixteenth location L16 at the
half portion
1217 of the distribution outlet 330 of the distribution conduit 328. In the
illustrated
embodiment, the shear stress increased by about 10% from the first location L1
at the
second feed inlet 325 to the sixteenth location L16 at the half portion 1217
of the
distribution outlet 330 of the distribution conduit 328.
[00375] For both flow conditions, the Reynolds number in FIG. 71 was reduced
from
the first location Li at the second feed inlet 325 to the sixteenth location
L16 at the half
portion 1217 of the distribution outlet 330 of the distribution conduit 328.
In the
illustrated embodiment, the Reynolds number was reduced from the first
location Li at
the second feed inlet 325 to the sixteenth location L16 at the half portion
1217 of the
distribution outlet 330 of the distribution conduit 328 by about 1/3. For both
flow
conditions, the Reynolds number at the sixteenth location L16 at the half
portion 1217 of
the distribution outlet 330 of the distribution conduit 328 is in the laminar
region.
88
TABLE II- DIMENSIONLESS FLOW CHARACTERISTICS (K = 50)
o
w
=
Inlet Velocity = 2.50 m/s
Inlet Velocity = 3.55 m/s .
.6.
'a
Location
c.,
c.,
Shear Calc Shear Shear Calc
Shear w
Velocity
Rate Visc. Stress Re Velocity
Rate Visc. Stress Re
.
L1 1.00 1.00 1.00 1.00 1.00 1.00 1.00
1.00 1.00 1.00
L2 1.00 1.18 0.87 1.02 1.15 1.00 1.20
0.85 1.03 1.17
L3 1.10 1.36 0.77 1.04 1.33 1.10 1.40
0.75 1.05 1.36
L4 1.00 1.30 0.80 1.04 1.18 0.99 1.32
0.79 1.04 1.19
L5 0.86 1.19 0.86 1.02 0.96 0.86 1.22
0.84 1.03 0.98 P
L6 0.83 1.23 0.83 1.03 0.86 0.83 1.28
0.81 1.03 0.89 03
,
L7 0.90 1.65 0.65 1.07 0.96 0.90 1.73
0.62 1.08 0.99
,
,
L8 0.90 1.73 0.62 1.08 0.85 0.90 1.80
0.60 1.08 0.88
L9 0.82 1.67 0.64 1.07 0.72 0.82 1.74
0.62 1.08 0.74
L10 0.77 1.63 0.65 1.07 0.64 0.77 1.73
0.62 1.08 0.68
L11 0.76 1.83 0.59 1.08 0.62 0.76 1.93
0.57 1.09 0.65
L12 0.78 1.84 0.59 1.08 0.63 0.78 1.92
0.57 1.09 0.65
L13 0.78 1.88 0.58 1.09 0.64 0.78 1.93
0.57 1.09 0.65
n
,-i
L14 0.78 1.88 0.58 1.09 0.64 0.78 1.95
0.56 1.09 0.66
cp
w
L15 0.78 1.85 0.59 1.09 0.63 0.78 1.92
0.57 1.09 0.65
..
(44
L16 0.79 1.89 0.58 1.09 0.65 0.79 1.98
0.55 1.09 0.67 'a
c.,
u,
oe
4.
(44
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
89
EXAMPLE 3
[00376] In
this Example, the half portion 1205 of the slurry distributor of FIG. 65 was
used to model the flow of gypsum slurry therethrough under flow conditions
similar to
those in Example 2 except that the value for the coefficient K in the Power
Law Model
(Eq. 2) was set at 100. The flow conditions were similar to those in Example 2
in other
respects.
[00377] Again, the flow characteristics were evaluated both for a feed
velocity of the
gypsum slurry into the second feed inlet 325 of 2.50 m/s and of 3.55 m/s. At
each
location L1-16, the following flow characteristics were determined: area-
weighted average
velocity (U), area-weighted average shear rate ()), viscosity calculated using
the Power
Law Model (Eq. 2), shear stress (Eq. 3), and Reynolds Number (Re) (Eq. 4).
Using the
inlet conditions, dimensionless values of the flow characteristics for each
location L1-16
were determined, as shown in Table III.
[00378] For both flow conditions where K was set equal to 100, the average
velocity
was reduced from the first location Li at the second feed inlet 325 to the
sixteenth
location L16 at the half portion 1217 of the distribution outlet 330 of the
distribution
conduit 328. In the illustrated embodiment, the average velocity was reduced
by about
1/5. The results for average velocity, on a dimensionless basis, were
substantially the
same as those in Example 2 and FIG. 67.
[00379] For both flow conditions, the shear rate increased from the first
location Li at
the second feed inlet 325 to the sixteenth location L16 at the half portion
1217 of the
distribution outlet 330 of the distribution conduit 328. In the illustrated
embodiment, the
shear rate approximately doubled from the first location Li at the second feed
inlet 325
to the sixteenth location L16 at the half portion 1217 of the distribution
outlet 330 of the
distribution conduit 328. The results for shear rate, on a dimensionless
basis, were
substantially the same as those in Example 2 and FIG. 68.
[00380] For both flow conditions, the calculated viscosity was reduced from
the first
location Li at the second feed inlet 325 to the sixteenth location L16 at the
half portion
1217 of the distribution outlet 330 of the distribution conduit 328. In the
illustrated
embodiment, the calculated viscosity was reduced from the first location Li at
the
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
second feed inlet 325 to the sixteenth location L16 at the half portion 1217
of the
distribution outlet 330 of the distribution conduit 328 by about half. The
results for the
calculated viscosity, on a dimensionless basis, were substantially the same as
those in
Example 2 and FIG. 69.
1003811 For both flow conditions, the shear stress increased from the first
location L1
at the second feed inlet 325 to the sixteenth location L16 at the half portion
1217 of the
distribution outlet 330 of the distribution conduit 328. In the illustrated
embodiment, the
shear stress increased by about 10% from the first location L1 at the second
feed inlet
325 to the sixteenth location L16 at the half portion 1217 of the distribution
outlet 330 of
the distribution conduit 328. The results for the shear stress, on a
dimensionless basis,
were substantially the same as those in Example 2 and FIG. 70.
[00382] For both flow conditions, the Reynolds number was reduced from the
first
location L1 at the second feed inlet 325 to the sixteenth location L16 at the
half portion
1217 of the distribution outlet 330 of the distribution conduit 328. In the
illustrated
embodiment, the Reynolds number was reduced from the first location L1 at the
second
feed inlet 325 to the sixteenth location L16 at the half portion 1217 of the
distribution
outlet 330 of the distribution conduit 328 by about 1/3. For both flow
conditions, the
Reynolds number at the sixteenth location L16 at the half portion 1217 of the
distribution
outlet 330 of the distribution conduit 328 is in the laminar region. The
results for the
Reynolds number, on a dimensionless basis, were substantially the same as
those in
Example 2 and FIG. 71.
[00383] FIGS. 67-71 are graphs of the flow characteristics computed for the
different
flow conditions of Examples 2 and 3. Curve-fit equations were used to describe
the
change in the flow characteristics over the distance between the feed inlet to
the half
portion of the distribution outlet. Accordingly, Examples 2 and 3 show that
the flow
characteristics are consistent over variations in inlet velocity and/or
viscosity.
TABLE III - DIMENSIONLESS FLOW CHARACTERISTICS (K = 100)
o
w
=
Location
Inlet Velocity = 2.50 m/s Inlet Velocity = 3.55 m/s .
.6.
'a
c,
Shear Calc Shear Shear Calc
Shear c,
w
Velocity Re Velocity
Re .
Rate Visc. Stress Rate Visc.
Stress .
L1 1.00 1.00 1.00 1.00 1.00 1.00 1.00
1.00 1.00 1.00
L2 1.00 1.16 0.88 1.02 1.13 1.00 1.21
0.85 1.03 1.18
L3 1.10 1.35 0.77 1.04 1.32 1.10 1.39
0.75 1.04 1.35
L4 1.00 1.28 0.80 1.03 1.17 1.00 1.35
0.77 1.04 1.22
L5 0.87 1.15 0.88 1.02 0.94 0.86 1.23
0.84 1.03 0.99 P
,9
00
L6 0.83 1.18 0.87 1.02 0.83 0.83 1.27
0.81 1.03 0.88 3
,J
1-
w
L7 0.90 1.60 0.66 1.06 0.93 0.90 1.70
0.63 1.07 0.98
0
L8
0.90 0.90 1.70 0.63 1.07 0.84 ' 0.90 1.77 0.61 1.08 0.87 ,
-
L9 0.82 1.61 0.66 1.07 0.69 0.82 1.71
0.63 1.07 0.73
L10 0.77 1.57 0.68 1.06 0.62 0.77 1.67
0.64 1.07 0.66
L11 0.76 1.76 0.61 1.08 0.60 0.76 1.88
0.58 1.09 0.64
L12 0.78 1.79 0.60 1.08 0.61 0.78 1.90
0.57 1.09 0.64
L13 0.78 1.81 0.60 1.08 0.62 0.78 1.93
0.57 1.09 0.65
n
,-i
L14 0.78 1.84 0.59 1.08 0.63 0.78 1.94
0.56 1.09 0.66
cp
w
L15 0.78 1.80 0.60 1.08 0.62 0.78 1.90
0.57 1.09 0.64 =
..
,...,
L16 0.79 1.87 0.58 1.09 0.64 0.79 1.96
0.56 1.09 0.67 'a
c,
u,
oe
4.
,...,
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
92
EXAMPLE 4
[003841 In this Example, the slurry distributor 2020 of FIG. 72 was used to
model the
flow of gypsum slurry at one of the bulb portions 2120 of the feed conduit
2022.
Referring to FIG. 72, the first and second entry segments 2036, 2037 of the
slurry
distributor 2020 each have a diameter D. The slurry distributor 2020 has a
length, along
the longitudinal axis, of about 12xD. The slurry distributor 2020 is
symmetrical about a
central longitudinal axis 50 extending generally in the machine direction
2192. The
slurry distributor 2020 can be separated into two half portions 2004, 2005
which are
substantially symmetrical about the central longitudinal axis.
[00385]
Referring to FIG. 73, the half portion 2004 of the slurry distributor of FIG.
72
was used to model the flow of gypsum slurry therethrough under flow conditions
similar
to those in Example 2 except using different dimensionless expressions of
velocity. An
inlet diameter D (x* = x/D) was selected as the length scale to non-
dimensionalize the
position vector x (x* = x/D), and an average inlet velocity (U) was used as
the velocity
scale to non-dimensionalize velocity vector u (u* = u/U). The flow conditions
were
similar to those in Example 2 in other respects.
[00386] Referring to FIGS. 73-76, a computational fluid dynamics (CFD)
technique
with a finite volume method was used to determine flow characteristics in the
half
portion of the distributor. In particular, average velocities at different
vertical locations
from the area A were calculated. The area extending about 0.75D from a center
of the
entry segment at area A was analyzed. Twelve radially-spaced vertical slices
were
analyzed to calculate twelve different average slurry velocities radially
around the bulb
portion. The twelve locations were substantially radially spaced apart such
that each
adjacent radial location is about 30 apart. Referring to FIGS. 75 and 76,
radial location
1 corresponds to a direction in opposing relationship to the machine direction
2192, and
radial location 7 corresponds to the machine direction 2192. Radial locations
4 and 10
are substantially aligned with the transverse axis 60.
[00387] The CFD technique was used with two different inlet velocity
conditions,
ui = U and u2 = 1.5U. The results of the CFD analysis are found in Table IV.
Magnitude of velocity is expressed as a dimensionless absolute value (jul* =
jul/U). The
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
93
data is also plotted in FIG. 77. It should be understood that the other half
portion 2005
of the slurry distributor 2020 would exhibit similar flow characteristics.
[00388] For both flow conditions, the average velocity at each radial location
1-12 was
less than the inlet velocity, but was greater than zero. The average velocity
ranged
from about half to about 7/8 of the inlet velocity (u* - 0.48 to 0.83 of the
inlet velocity).
The contoured convex dimple surface in the bulb portion helped redirect flow
from the
entry segment radially outward in all directions.
[00389] The slurry velocity also slowed down relative to the inlet velocity.
The
average velocity of all twelve radial locations for a given flow condition was
substantially
similar (- 0.65 or 65% of inlet velocity).
[00390] Also, in each flow condition, the highest average velocities occurred
at radial
locations 3-5 and 9-11. The higher average velocity along the transverse axis,
or along
the cross-machine direction 60, help provide more edge flow to the lateral
sidewalls.
[00391] Accordingly, this Example illustrates the bulb portion 2120 helps slow
down
the slurry and change the direction of the slurry from a downward vertical
direction to a
radially outward horizontal plane. Furthermore, the bulb portion 2120 helps
divert slurry
flow to the lateral outer and inner sidewalls of the shaped duct of the half
portion 2004
of the slurry distributor 2020 to encourage slurry movement in the cross-
machine
direction 60.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
94
TABLE IV ¨ DIMENSIONLESS RADIAL
VELOCITY DISTRIBUTION
Inlet Velocity U = U
1 U2 = 1.5 U
Location u* = u/Ui u* = WU2
R1 0.48 0.50
R2 0.56 0.60
R3 0.68 0.74
R4 0.76 0.72
R5 0.75 0.72
R6 0.60 0.49
R7 0.59 0.57
R8 0.58 0.58
R9 0.79 0.82
R10 0.79 0.83
R11 0.72 0.75
R12 0.53 0.61
Average u* 0.65 0.66
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
EXAMPLE 5
[00392] In this Example, the slurry distributor 2020 of FIG. 72 was used to
model the
flow of gypsum slurry at one of the shaped ducts 2041 of the feed conduit
2022.
Referring to FIG. 78, the half portion 2004 of the slurry distributor 2020 of
FIG. 72 was
used to model the flow of gypsum slurry therethrough under flow conditions
similar to
those in Example 2 except using a dimensionless expression of velocity similar
to that in
Example 4. In particular, the swirl motion of the slurry at the lateral inner
and outer
walls of the shaped duct was analyzed.
[00393] Referring to FIGS. 73, 74, and 78, a computational fluid dynamics
(CFD)
technique with a finite volume method was used to determine flow
characteristics in the
half portion 2004 of the distributor 2020. In particular, the swirl motion of
the slurry near
the lateral inner and outer sidewalls of the shaped duct 2041 was analyzed.
Referring
to FIG 73, the slurry moves in a swirling manner as it enters the shaped duct
2041. As
the slurry moves along the machine direction 2192 to the distribution outlet
2030, the
slurry streamlines become more ordered. The swirl motion of the slurry was
analyzed in
a region of the shaped duct 2041 at a longitudinal location of about 1-3/4 D
(1.72D) in
areas B1 and B2, as shown in FIGS. 74 and 78.
[00394] The swirl motion of the slurry is a function of its tangential
velocity and its
axial (or machine direction) velocity. Referring to FIG. 78, the degree of
swirl for
swirling flow is usually characterized by the swirl number (S) as the fluxes
of angular
and linear momentum using the following formula:
Momentum of Tangential Velocity Component
S=
Momentum of Axial Velocity Component
(Eq. 5)
fwurdr
with w = tangential velocity and u = axial velocity
fuurdr
and r represents the radial location.
[00395] If the average values of tangential velocity and axial velocity are
used in
Equation 5, it becomes:
Average Tangential Velocity = Wave
S
(Eq. 6)
Average Axial Velocity
Uave
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
96
For this Example, the characteristic swirl motion (Sm) is expressed using the
following
formula:
Maximum Tangential Velocity
(Eq. 7)
Average Axial Velocity
In this Example, the calculated swirl motion was used to calculate the swirl
angle using
the following formula:
Swirl Angle¨ tan" (S. ) (Eq. 8).
[00396] The CFD technique was used with two different dimensionless inlet
velocity
conditions, u1 = U and u2 = 1.5U. The results of the CFD analysis are found in
Table V.
It should be understood that the other half portion of the slurry distributor
would exhibit
similar flow characteristics. Through this analysis it has been found that in
embodiments, the slurry distributor can be constructed to produce a swirl
motion Sm in a
range from about zero to about 10 in the slurry distributor and a swirl angle
in a range
from about zero degrees to about 84 .
[00397] For both flow conditions, the maximum tangential velocity at the edges
was at
least about half of the inlet velocity in an edge region of the entry portion
of the shaped
duct. The swirl motion near the lateral sidewalls is expected to help maintain
the
cleanliness of the interior geometry of the slurry distributor while in use.
As shown in
FIG. 73, the swirl motion of the slurry decreases along the machine axis 50 in
the
direction of flow to the distribution outlet 2030.
TABLE V ¨ SWIRL MOTION
Ui = U U2 = 1.5 U
Inlet Velocity
u* = u/U/ u* = u/U2
MD Location = 1.72 D B1 B2 B1 B2
Max Tangential
0.50 0.75 0.55 0.74
Velocity
Ave Axial Velocity 0.71 0.63 0.67 -- 0.65 --
Lower Bound Upper Bound
Swirl Motion, Sm 0.71 1.19 0.82 1.14 0 10
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
97
Swirl Angle ( ) 35 50 39 49 0 84
EXAMPLE 6
[00398] In this Example, the slurry distributor 2020 of FIG. 72 was used to
model the
flow of gypsum slurry through the feed conduit 2022 and the distribution
conduit 2028.
Referring to FIGS. 73 and 74, the half portion 2004 of the slurry distributor
2020 of FIG.
72 was used to model the flow of gypsum slurry therethrough under flow
conditions
similar to those in Example 2 except using a dimensionless expression of
velocity
similar to that in Example 4.
[00399] For all flow conditions, the density (p) of the aqueous gypsum slurry
was set
at 1,000 kg/m3 and the viscosity K factor was set at 50. Again, the flow
characteristics
were evaluated both for a dimensionless feed velocity of the gypsum slurry
into the feed
inlet 2024 of B and of 1.5B. The following flow characteristics were
determined at each
successive dimensionless location downstream from the entry portion of the
shaped
duct 2041 along the machine direction 2192 expressed as a function of the
inlet
diameter D: area-weighted average velocity (U), area-weighted average shear
rate (2),
viscosity calculated using the Power Law Model (Eq. 2), and Reynolds Number
(Re)
(Eq. 4). The hydraulic diameter (Eq. 1) was also calculated at the noted
successive
dimensionless locations along the longitudinal axis 50. Using the inlet flow
conditions,
dimensionless values of the flow characteristics for each location were
determined, as
shown in Table VI.
[00400] FIGS. 79-82 are graphs of the flow characteristics computed for the
different
flow conditions of Example 6. Curve-fit equations were used to describe the
change in
the flow characteristics over the distance between the feed inlet to the half
portion 2004
of the distribution outlet 2030. Accordingly, the Examples show that the flow
characteristics are consistent over variations in inlet velocity.
[00401] For both flow conditions, the average velocity was reduced from the
first
location (about 3D) in the feed conduit to the last location (about 12D) at
the half portion
2117 of the distribution outlet 2030 of the distribution conduit 2028. The
average
velocity substantially progressively decreased as the slurry moved along the
machine
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
98
direction 2192. In the illustrated embodiment, the average velocity was
reduced by
about 1/3 from the inlet velocity, as shown in FIG. 79.
[00402] For both flow conditions, the shear rate increased from the first
location
(about 3D) in the feed conduit 2022 to the last location (about 12D) at the
half portion
2117 of the distribution outlet 2030 of the distribution conduit 2028. The
shear rate
varied from location to location. In the illustrated embodiment, the shear
rate increased
at the half portion 2117 of the distribution outlet 2030 of the distribution
conduit 2028
relative to the inlet, as shown in FIG. 80.
[00403] For both flow conditions, the calculated viscosity was reduced from
the first
location (about 3D) in the feed conduit to the last location (about 12D) at
the half portion
2117 of the distribution outlet 2030 of the distribution conduit 2028. The
calculated
viscosity varied from location to location. In the illustrated embodiment, the
calculated
viscosity decreased at the half portion 2117 of the distribution outlet 2030
of the
distribution conduit 2028 relative to the inlet, as shown in FIG. 81.
[00404] For both flow conditions, the Reynolds number in FIG. 82 was reduced
from
the first location (about 3D) in the feed conduit to the last location (about
12D) at the
half portion 2117 of the distribution outlet 2030 of the distribution conduit
2028. In the
illustrated embodiment, the Reynolds number decreased at half portion 2117 of
the
distribution outlet 2030 of the distribution conduit 2028 relative to the
inlet by about 1/2.
For both flow conditions, the Reynolds number at the half portion 2117 of the
distribution outlet 2030 of the distribution conduit 2028 is in the laminar
region.
[00405] Accordingly, it has been found that the distal half of the slurry
distributor
(between about 6D and about 12D) is configured to provide a flow stabilization
region in
which the average velocity of the slurry and the Reynolds number are generally
stable
and decreased relative to the feed inlet conditions. As shown in FIG. 73, the
slurry
moves in generally a streamline fashion along the machine direction 2192
through this
flow stabilization region.
TABLE VI- DIMENSIONLESS FLOW CHARACTERISTICS (K = 50)
Geometry Inlet Velocity = U1 Inlet
Velocity = U2
o=
o=
MD Hydraulic Shear Calc
Shear Calc
Velocity Re Velocity
Re
Distance Dia. Rate Visc. Rate
Visc.
3.11 0.35 0.74 1.08 0.93 0.55 0.75 1.09
0.93 0.56
4.31 0.31 0.74 1.19 0.86 0.53 0.75 1.21
0.85 0.54
5.51 0.31 0.71 1.17 0.87 0.50 0.72 1.18
0.86 0.50
6.71 0.31 0.68 1.11 0.91 0.46 0.69 1.12
0.91 0.46
7.91 0.32 0.66 1.05 0.95 0.44 0.66 1.06
0.95 0.44
8.92 0.31 0.66 1.07 0.94 0.43 0.66 1.07
0.94 0.43
9.93 0.31 0.66 1.09 0.93 0.43 0.66 1.09
0.93 0.43
10.94 0.30 0.66 1.11 0.91 0.43 0.66 1.11
0.91 0.43
11.95 0.30 0.66 1.13 0.89 0.43 0.66 1.14
0.89 0.43
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
100
EXAMPLE 7
[00406] In this Example, the slurry distributor 2020 of FIG. 72 was used to
model the
flow of gypsum slurry at the distribution outlet 2030 of the distribution
conduit 2028. In
this Example, the half portion 2004 of the slurry distributor of FIG. 73 was
used to model
the flow of gypsum slurry therethrough under flow conditions similar to those
in Example
2 except using a dimensionless expression of the width of the outlet opening
2081. A
dimensionless width (w/W) across the half portion 2119 of the outlet opening
2081 of
the distribution outlet 2030 (with a centerline at the transverse central
midpoint 2187
being equal to zero as shown in FIG. 72). The flow conditions were similar to
those in
Example 2 in other respects.
[00407] A CFD technique with a finite volume method was used to determine flow
characteristics in the half portion 2004 of the distributor 2020. In
particular, the angle of
spread of the slurry discharging from the outlet opening 2081 at various
locations
across the width of the half portion 2119 of the outlet opening 2081 of the
distribution
outlet 2030 was analyzed. The angle of spread was determined using the
following
formula:
angle of spread = taril(Vx/Vz),
(Eq. 9)
where Vx is the average velocity in the cross-machine direction and
Vz is the average velocity in the machine direction.
[00408] The angle of spread was calculated for two different conditions: one
in which
the profiling mechanism did not compress the outlet opening 2081 ("no
profiler") and
one in which the profiling mechanism compressed the outlet opening 2081
("profiler").
In the modeled slurry distributor 2020, the outlet opening 2081 has a height
of about 3/4
of an inch across its entire width of approximately ten inches for each half
portion 2004,
2005, for a total of twenty inches for the total width of the outlet opening
2081. The
modeled profiling mechanism has a profile member that is about 15 inches wide
and is
aligned with the transverse central midpoint such that a lateral portion of
the distribution
outlet is in offset relationship with the profiling member and is
uncompressed. In the
modeled "profiler" condition, the profiling mechanism compresses the outlet
opening by
about 1/8 of an inch such that the outlet opening is about 5/8 of an inch in
the area
CA 02888273 2015-04-16
WO 2014/066211 PCT/US2013/065843
101
underneath the profiling member. The angle of spread for both conditions was
determined, as shown in Table VII.
[00409] Under both conditions, the angle of spread increases as the location
moves
further outward from the transverse central midpoint 2187 (width = 0). The
angle of
spread is greatest at the lateral edge of the outlet opening 2081.
[00410] The angle of spread increased by using the profiling mechanism to
compress
the discharge outlet 2030, thereby reducing the height of the outlet opening
2081. In
the modeled "profiler" condition, the maximum angle of spread at the lateral
edge (width
= 0.466) increased over 25 percent relative to the "no profiler" condition. In
the "profiler"
condition, the average angle of spread increased by over 50 percent relative
to the "no
profiler" condition.
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
102
TABLE VII- SLURRY SPREAD ANGLE WITH
PROFILING MECHANISM
Outlet Width Location Spread Angle( )
(relative to centerline)
No Profiler Profiler
0.017 0.108 0.093
0.052 0.232 0.435
0.086 0.440 0.739
0.121 0.561 1.032
0.155 0.634 1.374
0.190 0.981 1.800
0.224 1.279 2.402
0.259 1.458 3.079
0.293 1.848 3.612
0.328 2.173 3.941
0.362 2.298 4.027
0.397 2.488 3.972
0.431 2.857 4.020
0.466 3.208 4.064
AVERAGE 1.469 2.471
CA 02888273 2015-04-16
WO 2014/066211
PCT/US2013/065843
103
[00411] All references, including publications, patent applications, and
patents,
cited herein are hereby incorporated by reference to the same extent as if
each
reference were individually and specifically indicated to be incorporated by
reference
and were set forth in its entirety herein.
[00412] The use of the terms "a" and "an" and "the" and similar referents in
the
context of describing the invention (especially in the context of the
following claims)
are to be construed to cover both the singular and the plural, unless
otherwise
indicated herein or clearly contradicted by context. The terms "comprising,"
"having,"
"including," and "containing" are to be construed as open-ended terms (i.e.,
meaning
"including, but not limited to,") unless otherwise noted. Recitation of ranges
of
values herein are merely intended to serve as a shorthand method of referring
individually to each separate value falling within the range, unless otherwise
indicated herein, and each separate value is incorporated into the
specification as if
it were individually recited herein. All methods described herein can be
performed in
any suitable order unless otherwise indicated herein or otherwise clearly
contradicted by context. The use of any and all examples, or exemplary
language
(e.g., "such as") provided herein, is intended merely to better illuminate the
invention
and does not pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as indicating
any
non-claimed element as essential to the practice of the invention.
[00413] Preferred embodiments of this invention are described herein,
including
the best mode known to the inventors for carrying out the invention.
Variations of
those preferred embodiments may become apparent to those of ordinary skill in
the
art upon reading the foregoing description. The inventors expect skilled
artisans to
employ such variations as appropriate, and the inventors intend for the
invention to
be practiced otherwise than as specifically described herein. Accordingly,
this
invention includes all modifications and equivalents of the subject matter
recited in
the claims appended hereto as permitted by applicable law. Moreover, any
combination of the above-described elements in all possible variations thereof
is
encompassed by the invention unless otherwise indicated herein or otherwise
clearly
contradicted by context.